Patent Application
20230240136
The present invention relates to a first and second organic semiconductor layer and an organic electronic device comprising the same. The invention further relates to a display device comprising the organic electronic device.
Organic electronic devices, such as organic light-emitting diodes OLEDs, which are self-emitting devices, have a wide viewing angle, excellent contrast, quick response, high brightness, excellent operating voltage characteristics, and color reproduction. A typical OLED comprises an anode, a hole transport layer HTL, an emission layer EML, an electron transport layer ETL, and a cathode, which are sequentially stacked on a substrate. In this regard, the HTL, the EML, and the ETL are thin films formed from organic compounds.
When a voltage is applied to the anode and the cathode, holes injected from the anode move to the EML, via the HTL, and electrons injected from the cathode move to the EML, via the ETL. The holes and electrons recombine in the EML to generate excitons. When the excitons drop from an excited state to a ground state, light is emitted. The injection and flow of holes and electrons should be balanced, so that an OLED having the above-described structure has excellent efficiency and/or a long lifetime.
Performance of an organic light emitting diode may be affected by characteristics of the semiconductor layer, and among them, may be affected by characteristics of an organic material of the semiconductor layer.
Particularly, development of a semiconductor layer being capable of increasing electron mobility and simultaneously increasing electrochemical stability is needed so that the organic electronic device, such as an organic light emitting diode, may be applied to a large-size flat panel display.
Further, development of a semiconductor layer being capable to have an extended life span at higher current density and thereby at higher brightness is needed. In particular the development of an organic semiconductor materials or semiconductor layer is needed with respect to lowering the operating voltage, which is important for reducing power consumption and increasing battery life, for example of a mobile display device.
There remains a need to improve performance of organic semiconductor materials, semiconductor layers, as well as organic electronic devices thereof, in particular to achieve increased lifetime through improving the characteristics of the compounds comprised therein.
An aspect of the present invention provides an organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer comprises:
a metal dopant, and
a compound of Formula (I):
Hetero atoms, if not otherwise stated, may be individually selected from N, O, S, B, Si, P, Se, preferably from N, O and S and more preferred is N.
According to one embodiment the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode;
wherein
a) the first organic semiconductor layer comprises:
a metal dopant, and
a compound of Formula (I):
According to one embodiment the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer comprises:
a metal dopant, and
a compound of Formula (I):
According to one embodiment the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer comprises:
a metal dopant, and
a compound of Formula (I):
According to one embodiment L is a substituted or unsubstituted C6 to C18 arylene, a substituted or unsubstituted C3 to C18 heteroarylene, a substituted or unsubstituted phenylene, a substituted or unsubstituted biphenylene, a substituted or unsubstituted terphenylene, a substituted or unsubstituted anthracenylene, a substituted or unsubstituted dibenzofuranylene, a substituted or unsubstituted dibenzothiophenylene, a substituted or unsubstituted carbazolylene, a substituted or unsubstituted pyridinylene, a substituted or unsubstituted phenylpyridinylene, a substituted or unsubstituted quinolinylene.
According to one embodiment L is not a single bond.
According to one embodiment the substituents of L, Ar1, Ar2, Ar3, Ar4 and/or N are not H.
According to one embodiment the substituents of L, Ar1, Ar2, Ar3, Ar4 and/or N are independently selected from:
If not, otherwise stated H can represent hydrogen or deuterium.
If not otherwise stated the final syllable “ene” for the group members of Ar3 for n=0 or if considered by an expert may be “yl”. For example for n=0, the group members of Ar3 may be read or replaced with “substituted or unsubstituted C6 to C36 aryl, substituted or unsubstituted C3 to C36 heteroaryl group, substituted or unsubstituted C3 to C36 heteroaryl group, a substituted pyrazinyl, a substituted pyrimidinyl, a substituted or unsubstituted acridinyl, a substituted or unsubstituted benzoacridinyl, a substituted or unsubstituted dibenzoacridinyl, a substituted or unsubstituted dibenzofuranyl, a substituted or unsubstituted carbazolyl, a substituted or unsubstituted benzoquinolinyl, a substituted or unsubstituted phenanthridinyl, a substituted or unsubstituted phenanthrolinyl, a substituted or unsubstituted dinaphthofuranyl, substituted or unsubstituted benzo[4,5]imidazo[1,2-a]quinolinyl, or a substituted or unsubstituted dinaphthothiophenyl”.
According to one embodiment L may be selected from an unsubstituted phenylene or an unsubstituted biphenylene.
According to one embodiment, wherein the second organic semiconductor layer may comprise at least one radialene compound, wherein the total amount of electron withdrawing groups in the radialene compound is from 13 atomic percent to 90 atomic percent.
According to one embodiment, wherein the electron withdrawing group may be selected from the group comprising a halide, nitrile, perhalogenated C1 to C20 alkyl, perhalogenated C6 to C20 aryl, perhalogenated heteroaryl with 6 to 20 ring-forming atoms, preferably the electron withdrawing group is a fluoride, perfluroinated C1 to C2 alkyl, perfluorinated C6 to C20 aryl, perfluorinated heteroaryl with 5 to 20 ring-forming atoms or CN.
According to one embodiment, wherein the electron withdrawing group may be preferably independently selected from the group consisting of fluorine, chlorine, bromine and CN.
According to one embodiment, wherein the second organic semiconductor layer may comprise at least one radialene compound, wherein the total amount of electron withdrawing groups in the radialene compound is from 13 atomic percent to 90 atomic percent; and wherein the electron withdrawing group may be selected from the group comprising a halide, nitrile, perhalogenated C1 to C20 alkyl, perhalogenated C6 to C20 aryl, perhalogenated heteroaryl with 6 to 20 ring-forming atoms, preferably the electron withdrawing group is a fluoride, perfluroinated C1 to C2 alkyl, perfluorinated C to C20 aryl, perfluorinated heteroaryl with 5 to 20 ring-forming atoms or CN.
According to one embodiment, wherein the second organic semiconductor layer may comprise at least one radialene compound, wherein the total amount of electron withdrawing groups in the radialene compound is from 13 atomic percent to 90 atomic percent; and wherein the electron withdrawing may be preferably independently selected from the group consisting of fluorine, chlorine, bromine and CN.
According to one embodiment, the organic electronic device may comprise an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
wherein,
wherein
According to one embodiment, the organic electronic device may comprise an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
b) the second organic semiconductor layer may comprise at least one radialene compound, wherein the radialene compound is a [3]-radialene, and preferably the radialene compound is a [3]-radialene and selected from the group A1 to A21.
According to one embodiment, the organic electronic device may comprise an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
b) the second organic semiconductor layer may comprise at least one radialene compound, preferably the radialene compound is a [3]-radialene, and furthermore preferred the radialene compound is a [3]-radialene and selected from the group A1 to A21.
According to one embodiment, the organic electronic device may comprise an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
b) the second organic semiconductor layer may comprise at least one radialene compound, preferably the radialene compound is a [3]-radialene, and furthermore preferred the radialene compound is a [3]-radialene and selected from the group A1 to A21.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
b) the second organic semiconductor layer may comprise at least one radialene compound, preferably the radialene compound is a [3]-radialene, and furthermore preferred the radialene compound is a [3]-radialene and selected from the group A1 to A21.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
b) the second organic semiconductor layer may comprise at least one radialene compound, preferably the radialene compound is a [3]-radialene, and furthermore preferred the radialene compound is a [3]-radialene and selected from the group A1 to A21.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
b) the second organic semiconductor layer may comprise at least one radialene compound, preferably the radialene compound is a [3]-radialene, and furthermore preferred the radialene compound is a [3]-radialene and selected from the group A1 to A21.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
b) the second organic semiconductor layer may comprise at least one radialene compound, preferably the radialene compound is a [3]-radialene, and furthermore preferred the radialene compound is a [3]-radialene and selected from the group A1 to A21.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
b) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
b) the second organic semiconductor layer may comprise at least one radialene compound, preferably the radialene compound is a [3]-radialene, and furthermore preferred the radialene compound is a [3]-radialene and selected from the group A1 to A21.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) the hetero atom of the C3 to C36 heteroaryl, C3 to C24 heteroaryl, C3 to C20 heteroaryl, C3 to C18 heteroarylene, C12 to C25 heteroarylene, C3 to C12 heteroaryl, C3 to C12 heteroarylene, may be selected from N, O or S.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) the hetero atom of the heteroaryl and/or heteroarylene, may be selected from N or O.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) the hetero atom of the heteroaryl and/or heteroarylene, may be selected from N.
According to a further preferred embodiment, wherein
a) the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise a metal dopant, and
wherein
b) the second organic semiconductor layer may comprise at least one radialene compound, preferably the radialene compound is a [3]-radialene, and furthermore preferred the radialene compound is a [3]-radialene and selected from the group A1 to A21.
According to a further preferred embodiment, wherein
a) the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise a metal dopant, and
wherein
b) the second organic semiconductor layer may comprise at least one radialene compound, preferably the radialene compound is a [3]-radialene, and furthermore preferred the radialene compound is a [3]-radialene and selected from the group A1 to A21.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) n may be selected 0, 1, 2, 3 or 4, or preferably n may be selected 0, 1, 2 or 3, or further preferred n may be selected 0, 1 or 2, or in addition preferred n may be selected 0 or 1, also preferred n may be selected 2 or 3.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) R1, R2 may be independently selected from substituted or unsubstituted C1 to C16 alkyl, substituted or unsubstituted C6 to C12 aryl, substituted or unsubstituted C3 to C17 heteroaryl.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) R1, R2 may be independently selected from unsubstituted C6 to C18 aryl, or unsubstituted C3 to C24 heteroaryl. According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) R2 may be preferably independently selected from methyl.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) Ar4 may be independently selected from phenyl, biphenyl, terphenyl, naphthyl, phenanthrenyl, pyridyl, quinolinyl, quinazolinyl.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) Ar4 may be independently selected from phenyl, biphenyl, terphenyl, naphthyl, phenanthrenyl.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) Ar4 may be independently selected from phenyl and biphenyl and more preferred from phenyl.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I):
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I):
L may be a single bond or may be selected from an unsubstituted phenylene, an unsubstituted biphenylene, an unsubstituted terphenylene, an unsubstituted anthracenylene, an unsubstituted dibenzofuranylene, an unsubstituted dibenzothiophenylene, an unsubstituted an unsubstituted pyridinylene, a substituted or unsubstituted phenylpyridinylene, preferably L may be a single bond or may be selected from unsubstituted phenylene or unsubstituted biphenylene.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I):
L may be selected from unsubstituted phenylene or unsubstituted biphenylene preferably L may be selected from unsubstituted phenylene.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) Ar3 is a group may be selected from a substituted pyrazinylene, a substituted pyrimidinylene, a substituted or unsubstituted dibenzofuranylene, a substituted or unsubstituted carbazolylene, a substituted or unsubstituted benzoquinolinylene, a substituted or unsubstituted phenanthridinylene, a substituted or unsubstituted phenanthrolinylene, a substituted or unsubstituted dinaphthofuranylene, substituted or unsubstituted benzo[4,5]imidazo[1,2-a]quinolinylene, or a substituted or unsubstituted dinaphthothiophenylene.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) Ar3 is a group may be selected from a substituted pyrazinylene, a substituted pyrimidinylene, an unsubstituted benzoacridinylene or an unsubstituted dibenzoacridinylene.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I):
According to another embodiment, the second organic semiconductor layer and/or the second organic semiconductor layer of the organic electronic device may comprise at least one radialene compound, wherein preferably the radialene compound is a [3]-radialene, and furthermore preferred the [3]-radialene may be selected from A1 to A21:
According to one embodiment, wherein the second organic semiconductor layer may comprise at least one radialene compound, wherein the total amount of electron withdrawing groups in the radialene compound is from 13 atomic percent to 90 atomic percent; and wherein the electron withdrawing may be preferably independently selected from the group consisting of fluorine, chlorine, bromine and CN.
In the specification the amount of electron withdrawing groups in the sum formula of a radialene compound is given in atomic percent (at %) of electron withdrawing groups of the total number of atoms in the sum formula.
For clarity of definition and calculation, the sum formula is simplified in a way that one electron withdrawing group is counted as one atomic unit even if it consists of more than one atom.
According to the invention an electron withdrawing group is defined to be selected from the group of fluorine, chlorine, bromine and/or CN only.
The CN-group is counted as one electron withdrawing group in the (simplified) sum formula of the radialene compound.
The amount of electron withdrawing groups of a radialene compound can be calculated using formula given in Table A. The amount of electron withdrawing groups of radialene compounds as examples are shown in Table A.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) L may be independently selected from B1 to B21:
wherein the asterisk symbol “*” represents the binding position of L.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) Ar3 may be independently selected from E1 to E9:
wherein the asterisk symbol “*” represents the binding position of Ar3 to L and if n=1, 2, 3 or 4 Ar4 bonds to a carbon of Ar3 excluding the binding position of Ar3 to L.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) Ar4 may be independently selected from hydrogen or F1 to F13:
wherein the asterisk symbol “*” represents the binding position of Ar4 to Ar3, and Ar4 bonds to a carbon of Ar3 excluding the binding position of Ar3 to L.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein according to Formula (I) Ar3-(Ar4)n may be independently selected from D1 to D33:
wherein the asterisk symbol “*” represents the binding position of Ar3 to L.
According to another embodiment, the compound of formula (I), the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise the compound of Formula (I), wherein the compound of Formula (I) may be selected from G1 to G53:
The metal dopant of the present invention may have the following characteristics:
(i) the metal dopant of the present invention is an electrical n-dopant, and/or
(ii) the purpose of an electrical n-dopant is improvement of electrical properties of semiconducting devices, particularly, decrease of electrical resistances in the device and thus decrease of operational voltage of the device, and/or
(iii) the metal dopant does not emit light/is essentially non-emissive, and/or
(iv) it can be supposed that the metal in the metal dopant is at least partially in its substantially elemental form, and/or
(v) the substantially elemental form of a metal as present in the semiconducting material/layer of the invention is the form which is obtainable by vaporization of
a neat form or an alloy of the metal and by co-deposition of metal vapor formed this way with vapor of the compound represented by Formula (I) on a solid support, and/or
(vi) it can be supposed that from a chemical point of view, at least part of metal atoms present in the substantially elemental form of a metal has oxidation degree zero.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device, wherein the metal of the metal dopant may have an electronegativity of about ≥0.7 to about ≤1.3 according to Pauling scale, and preferably the metal dopant has an electronegativity of about ≥0.9 to about ≤1.2, further preferred about ≥1 to about ≤1.1.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise a metal dopant, wherein the metal dopant is:
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise a metal dopant, wherein the metal dopant is a metal selected from the group consisting of alkali metals, alkaline earth metals and rare earth metals preferably the metal is selected from Li, Na, Cs, Mg, Ca, Sr, Sm or Yb and more preferably the metal is selected from Li, Cs, Mg or Yb.
According to another embodiment, the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may comprise a metal dopant, wherein the metal dopant is a metal selected from Li or Yb.
According to one embodiment, wherein the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may consists of a compound of Formula (I) and a metal dopant, wherein the metal dopant is a metal from the group consisting of alkali metals, alkaline earth metals and rare earth metals preferably the metal is selected from Li, Na, Cs, Mg, Ca, Sr, Sm or Yb and more preferably the metal is selected from Li, Cs, Mg or Yb.
According to one embodiment, wherein the first organic semiconductor layer and/or the first organic semiconductor layer of the organic electronic device may consist of a compound of Formula (I) and a metal dopant, wherein the metal dopant is a metal selected from Li or Yb.
The compound of formula (1) and/or the metal dopant may be essentially non-emissive.
According to another aspect a first organic semiconductor layer may comprises at least one composition of the present invention.
The first organic semiconductor layer comprising the composition of the present invention may be essentially non-emissive.
The thickness of the first organic semiconductor layer may be from about 0.5 nm to about 100 nm, for example about 2 nm to about 40 nm. When the thickness of the first organic semiconductor layer is within these ranges, the first organic semiconductor layer may have improved charge transport ability without a substantial increase in operating voltage.
The first organic semiconductor layer comprising the composition of the present invention may have strong electron transport characteristics to increase charge mobility and/or stability.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
wherein
b) the second organic semiconductor layer comprises at least one radialene compound.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
wherein
n may be 0, 1, 2, 3 or 4; and
b) the second organic semiconductor layer comprises at least one radialene compound.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
wherein
n may be 0, 1, 2, 3 or 4; and
b) the second organic semiconductor layer comprises at least one radialene compound.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
wherein
n may be 0, 1, 2, 3 or 4; and
b) the second organic semiconductor layer comprises at least one radialene compound.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
wherein
n may be 0, 1, 2, 3 or 4; and
b) the second organic semiconductor layer comprises at least one radialene compound.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
wherein
n may be 0, 1, 2, 3 or 4; and
b) the second organic semiconductor layer comprises at least one radialene compound.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
wherein
n may be 0, 1, 2, 3 or 4; and
b) the second organic semiconductor layer comprises at least one radialene compound.
According to one embodiment, the organic electronic device comprising an anode, a first organic semiconductor layer, a second organic semiconductor layer and a cathode; wherein
a) the first organic semiconductor layer may comprise:
a metal dopant, and
a compound of Formula (I):
wherein
n may be 0, 1, 2, 3 or 4; and
b) the second organic semiconductor layer comprises at least one radialene compound.
According to another aspect a compound may be represented by the following Formula (I):
wherein
According to one embodiment, wherein the compound may be represented by the following Formula (I):
According to another aspect a compound may be represented by the following Formula (I):
According to another aspect a compound may be represented by the following Formula (I):
According to another aspect a compound may be represented by the following Formula (I):
According to another aspect a compound may be represented by the following Formula (I):
According to another aspect a compound may be represented by the following Formula (I):
According to another aspect a compound may be represented by the following Formula (I):
wherein
According to another aspect a compound may be represented by the following Formula (I):
wherein
According to another aspect a compound may be represented by the following Formula (I):
wherein
According to one embodiment, wherein the compound may be represented by the Formula (I), wherein L may be selected from an unsubstituted phenylene or an unsubstituted biphenylene.
According to one embodiment, wherein the compound may be represented by the Formula (I), wherein L may be selected from an unsubstituted phenylene.
According to another aspect an electronic device may comprises a first organic semiconductor layer and a second organic semiconductor layer in accordance with the invention.
According to another aspect an electronic device may comprises an anode, a cathode and a first organic semiconductor layer and a second organic semiconductor layer, wherein the organic electronic device further comprises at least one emission layer and the first organic semiconductor layer is arranged between the at least one emission layer and the cathode and the second organic semiconductor layer is arranged between the at least one emission layer and the anode.
According to another aspect the first organic semiconductor layer may be arranged between the at least one emission layer and the cathode and the second organic semiconductor layer may be arranged between the at least one emission layer and the anode, wherein the first organic semiconductor layer is in direct contact with the cathode the second organic semiconductor layer is in direct contact with the anode.
According to another aspect the organic electronic device may comprise in addition a first and a second emission layer and the first and the second organic semiconductor layer are arranged between the at least one emission layer and the cathode, and between a first and a second emission layer; and the first organic semiconductor layer is in direct contact with the second organic semiconductor layer.
The electronic device of the present invention may further comprise at least one emission layer, wherein the first organic semiconductor layer of the present invention is arranged between the at least one emission layer and the cathode, preferably the first organic semiconductor layer is an electron transport layer, and the second organic semiconductor layer is a hole injection layer.
According to another aspect the organic electronic device may comprises in addition a charge generation layer (CGL), wherein CGL comprises a p-type charge generation layer (p-CGL) and n-type charge generation layer (n-CGL) and charge generation layer may be arranged between the at least one emission layer and the cathode and between a first and a second emission layer.
According to another aspect the organic electronic device may comprises in addition a p-type charge generation layer (CGL) and the first organic semiconductor layer may be arranged between the at least one emission layer and the cathode, and the first organic semiconductor layer is in direct contact with a p-type charge generation layer (CGL), and the second organic semiconductor layer may be arranged between first organic semiconductor layer and the cathode.
The first organic semiconductor layer comprising a compound of Formula (I) and a metal dopant of the present invention may have strong electron transport characteristics to increase charge mobility and/or stability and thereby to improve luminance efficiency, voltage characteristics, and/or lifetime characteristics of an electronic device, and the second organic semiconductor layer comprises the radialene compound and the radialene compound is selected from a [3]-radialene.
The electronic device of the present invention may further comprise a photoactive layer, wherein the first organic semiconductor layer of the present invention is arranged between the photoactive layer and the cathode layer, preferably between an emission layer or light-absorbing layer and the cathode layer, preferably the first organic semiconductor layer is an electron transport layer, and the second organic semiconductor layer hole injection layer.
An organic electronic device according to one embodiment may comprise the first organic semiconductor layer and second organic semiconductor layer in accordance with the present invention, at least one anode layer, at least one cathode layer and at least one emission layer.
According to one embodiment the organic electronic device according to one embodiment may comprise the first organic semiconductor layer and second organic semiconductor layer in accordance with the present invention, at least one anode layer, at least one cathode layer and at least one emission layer, wherein the first organic semiconductor layer may be arranged between the emission layer and the cathode layer and the second organic semiconductor layer may be arranged between the at least one emission layer and the anode.
An organic electronic device according to the present invention can be a light emitting device, thin film transistor, a battery, a display device or a photovoltaic cell, and preferably a light emitting device. A light emitting device can be an OLED.
According to one embodiment the OLED may have the following layer structure, wherein the layers having the following order:
an anode layer, a hole injection layer, optional a first hole transport layer, optional a second hole transport layer, an emission layer, a first electron transport layer comprising the compound of Formula (I) and a metal dopant according to the invention, a hole injection layer comprising at least one radialene compound according to the invention, an electron injection layer, and a cathode layer.
According to another aspect of the present invention, there is provided a method of manufacturing an organic electronic device, the method using:
The methods for deposition that can be suitable comprise:
According to various embodiments of the present invention, there is provided a method using:
According to various embodiments of the present invention, the method may further include forming on the anode electrode an emission layer and at least one layer selected from the group consisting of forming a hole transport layer, or forming a hole blocking layer, between the anode electrode and the first organic semiconductor layer.
According to various embodiments of the present invention, the method may further include the steps for forming an organic light-emitting diode (OLED), wherein
According to one embodiment of the present invention first organic semiconductor layer is an electron transport layer and second organic semiconductor layer is a hole injection layer.
According to one embodiment of the present invention first organic semiconductor layer is an electron transport layer and second organic semiconductor layer is a hole injection layer and/or a p-type charge generation layer.
According to one embodiment of the present invention first organic semiconductor layer is an n-type charge generation layer and second organic semiconductor layer is a hole injection layer.
According to one embodiment of the present invention first organic semiconductor layer is n-type charge generation layer and second organic semiconductor layer is a hole injection layer and/or a p-type charge generation layer.
According to one embodiment of the present invention first organic semiconductor layer is electron transport layer and/or n-type charge generation layer and second organic semiconductor layer is a hole injection layer and/or a p-type charge generation layer.
According to various embodiments of the present invention, the method may further include forming an electron injection layer on a first electron transport layer. However, according to various embodiments of the OLED of the present invention, the OLED may not comprise an electron injection layer.
According to another aspect of the invention, it is provided an electronic device comprising at least one organic light emitting device according to any embodiment described throughout this application, preferably, the electronic device may comprise the organic light emitting diode in one of embodiments described throughout this application. More preferably, the electronic device is a display device.
The term “radialene” means alicyclic organic compounds which contain n-cross-conjugated double bonds. Radialene may comprise substituents which may be selected from electron withdrawing group.
The term “electron withdrawing group” means a species that draws electron towards itself. Examples of electron withdrawing groups are halogens, nitriles etc.
The term “organic metal complex” means a compound which comprises one or more metal and one or more organic groups. The metal may be bound to the organic group via a covalent or ionic bond. The organic group means a group comprising mainly covalently bound carbon and hydrogen atoms. The organic group may further comprise heteroatoms selected from N, O, S, B, Si, P, Se, preferably from B, N, O and S.
In the context of the present specification the term “essentially non-emissive” means that the contribution of the compound of Formula (I) and/or layer and/or metal dopant to the visible emission spectrum from the device is less than 10%, preferably less than 5% relative to the visible emission spectrum. The visible emission spectrum is an emission spectrum with a wavelength of about ≥380 nm to about ≤780 nm. Preferably, a first organic semiconductor layer or a device comprising a layer, which comprises the compound of Formula (I) and at least one a metal selected from Li, Na, Cs, Mg, Ca, Sr, Sm or Yb preferably Li, Cs, Mg or Yb and more preferably Li and Yb.
The term “free of”, “does not contain”, “does not comprise” does not exclude impurities which may be present in the compounds prior to deposition. Impurities have no technical effect with respect to the object achieved by the present invention.
The operating voltage, also named U, is measured in Volt (V) at 10 milliAmpere per square centimeter (mA/cm2).
The candela per Ampere efficiency, also named cd/A efficiency, is measured in candela per ampere at 10 milliAmpere per square centimeter (mA/cm2).
The external quantum efficiency, also named EQE, is measured in percent (%).
The color space is described by coordinates CIE-x and CIE-y (International Commission on Illumination 1931). For blue emission the CIE-y is of particular importance. A smaller CIE-y denotes a deeper blue color.
The highest occupied molecular orbital, also named HOMO, and lowest unoccupied molecular orbital, also named LUMO, are measured in electron volt (eV).
The rate onset temperature is measured in ° C. and describes the VTE source temperature at which measurable evaporation of a compound commences at a pressure of less than 10−5 mbar.
The term “OLED”, “organic light emitting diode”, “organic light emitting device”, “organic optoelectronic device” and “organic light-emitting diode” are simultaneously used and have the same meaning.
The term “transition metal” means and comprises any element in the d-block of the periodic table, which comprises groups 3 to 12 elements on the periodic table.
The term “group III to VI metal” means and comprises any metal in groups III to VI of the periodic table.
As used herein, “weight percent”, “wt.-%”, “percent by weight”, “% by weight”, and variations thereof refer to a composition, component, substance or agent as the weight of that composition, component, substance or agent of the respective electron transport layer divided by the total weight of the composition thereof and multiplied by 100. It is understood that the total weight percent amount of all components, substances or agents of the respective electron transport layer are selected such that it does not exceed 100 wt.-%.
As used herein, “volume percent”, “vol.-%”, “percent by volume”, “% by volume”, and variations thereof refer to an elemental metal, a composition, component, substance or agent as the volume of that elemental metal, component, substance or agent of the respective electron transport layer divided by the total volume of the respective electron transport layer thereof and multiplied by 100. It is understood that the total volume percent amount of all elemental metal, components, substances or agents of the respective cathode electrode layer are selected such that it does not exceed 100 vol.-%.
All numeric values are herein assumed to be modified by the term “about”, whether or not explicitly indicated. As used herein, the term “about” refers to variation in the numerical quantity that can occur.
Whether or not modified by the term “about”, the claims include equivalents to the quantities.
It should be noted that, as used in this specification and the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the content clearly dictates otherwise.
It should be noted that, as used in this specification and the appended claims, “*” if not otherwise defined indicates the chemical bonding position.
The anode electrode and cathode electrode may be described as anode electrode/cathode electrode or anode electrode/cathode electrode or anode electrode layer/cathode electrode layer.
In the present specification, when a definition is not otherwise provided, an “alkyl group” may refer to an aliphatic hydrocarbon group. The alkyl group may refer to “a saturated alkyl group” without any double bond or triple bond. The alkyl group may be a linear, cyclic or branched alkyl group.
The alkyl group may be a C1 to C16 alkyl group, or preferably a C1 to C12 alkyl group. More specifically, the alkyl group may be a C1 to C14 alkyl group, or preferably a C1 to C10 alkyl group or a C1 to C6 alkyl group. For example, a C1 to C4 alkyl group comprises 1 to 4 carbons in alkyl chain, and may be selected from methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, and t-butyl.
Specific examples of the alkyl group may be a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and the like.
In the present specification, “aryl” and “arylene group” may refer to a group comprising at least one hydrocarbon aromatic moiety, and all the elements of the hydrocarbon aromatic moiety may have p-orbitals which form conjugation, for example a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, a fluorenyl group and the like.
The term “heteroaryl” and “heteroarylene” may refer to aromatic heterocycles with at least one heteroatom, and all the elements of the aromatic heterocycle may have p-orbitals which form conjugation, for example a pyridyl, pyrimidyl, pyrazinyl, triazinyl, pyrrolyl, carbazolyl, furanyl, benzofuranyl, dibenzofuranyl, thiophenyl, benzothiophenyl, dibenzothiophenyl group and the like. Preferably, the aromatic heterocycles are free of sp3-hybridised carbon atoms.
The term “substituted or unsubstituted heteroaryl”, “substituted or unsubstituted C5 to C24 heteroaryl”, “substituted or unsubstituted C3 to C24 heteroaryl”, “substituted or unsubstituted C5 to C18 heteroaryl”, “substituted or unsubstituted C5 to C17 heteroaryl”, “substituted or unsubstituted C3 to C17 heteroaryl”, “substituted or unsubstituted C3 to C12 heteroarylene” and the like means that the substituted or unsubstituted heteroaryl comprises at least one heteroaryl ring; or at least one heteroaryl ring and at least one non-heteroaryl ring; or at least two heteroaryl rings and at least one non-heteroaryl ring; or at least three heteroaryl rings and at least one non-heteroaryl ring; or at least one heteroaryl ring and at least two non-heteroaryl rings. The rings of the substituted or unsubstituted heteroaryl can be a fused.
The term “hetero-fluorene ring” refers to a dibenzo[d,d]furanyl, dibenzo[b,d]thiophenyl or dibenzo[b,d]selenophenyl group.
The heteroatom may be selected from N, O, S, B, Si, P, Se, preferably from N, O and S.
A heteroarylene ring may comprise at least 1 to 3 heteroatoms. Preferably a heteroarylene ring may comprise at least 1 to 3 heteroatoms individually selected from N, S and/or O.
Further preferred in addition to the compounds of Formula (I) at least one additional heteroaryl/ene ring may comprise at least 1 to 3 N-atoms, or at least 1 to 2-N atoms or at least one N-atom.
Further preferred in addition to the compounds of Formula (I) at least one additional heteroaryl/ene ring may comprise at least 1 to 3 O-atoms, or at least 1 to 2 O-atoms or at least one O-atom.
Further preferred in addition to the compounds of Formula (I) at least one additional heteroaryl/ene ring may comprise at least 1 to 3 S-atoms, or at least 1 to 2 S-atoms or at least one S-atom.
According to another preferred embodiment the compound according to Formula (I) may comprise:
According to one embodiment the compound according to Formula (I):
According to one embodiment the compound according to Formula (I) can be free of a fluorene ring and free of a hetero-fluorene ring.
According to one embodiment the compound according to Formula (I) can be free of a spiro-group.
According to a further preferred embodiment the compound of Formula (I) comprises at least 2 to 7, preferably 2 to 5, or 2 to 3 hetero aromatic rings.
According to a further preferred embodiment the compound of Formula (I) comprises at least 2 to 7, preferably 2 to 5, or 2 to 3 hetero aromatic rings, wherein at least one of the aromatic rings is a five-member hetero aromatic ring.
According to a further preferred embodiment the compound of Formula (I) comprises at least 3 to 7, preferably 3 to 6, or 3 to 5 hetero aromatic rings, wherein at least two of the hetero aromatic rings are five member hetero-aromatic-rings.
According to one embodiment the compound according to Formula (I) may comprise at least 6 to 12 non-hetero aromatic rings and 2 to 3 hetero aromatic rings.
According to one preferred embodiment the compound according to Formula (I) may comprise at least 7 to 12 non-hetero aromatic rings and 2 to 5 hetero aromatic rings.
According to one preferred embodiment the compound according to Formula (I) may comprise at least 7 to 11 non-hetero aromatic rings and 2 to 3 hetero aromatic rings.
The melting point (mp) is determined as peak temperatures from the DSC curves of the above TGA-DSC measurement or from separate DSC measurements (Mettler Toledo DSC822e, heating of samples from room temperature to completeness of melting with heating rate 10 K/min under a stream of pure nitrogen. Sample amounts of 4 to 6 mg are placed in a 40 μL Mettler Toledo aluminum pan with lid, a <1 mm hole is pierced into the lid).
According to another embodiment the compound of Formula (I) may have a melting point of about ≥220° C. and about ≤380° C., preferably about ≥260° C. and about ≤370° C., further preferred about ≥265° C. and about ≤360° C.
The glass transition temperature is measured under nitrogen and using a heating rate of 10 K per min in a Mettler Toledo DSC 822e differential scanning calorimeter as described in DIN EN ISO 11357, published in March 2010.
According to another embodiment the compound of Formula (I) may have a glass transition temperature Tg of about ≥105° C. and about ≤380° C., preferably about ≥110° C. and about ≤350° C.
The rate onset temperature is determined by loading 100 mg compound into a VTE source. As VTE source a point source for organic materials is used as supplied by Kurt J. Lesker Company (www.lesker.com) or CreaPhys GmbH (http://www.creaphys.com). The VTE source is heated at a constant rate of 15 K/min at a pressure of less than 10−5 mbar and the temperature inside the source measured with a thermocouple. Evaporation of the compound is detected with a QCM detector which detects deposition of the compound on the quartz crystal of the detector. The deposition rate on the quartz crystal is measured in {acute over (Å)}ngstrom per second. To determine the rate onset temperature, the deposition rate is plotted against the VTE source temperature. The rate onset is the temperature at which noticeable deposition on the QCM detector occurs. For accurate results, the VTE source is heated and cooled three time and only results from the second and third run are used to determine the rate onset temperature.
To achieve good control over the evaporation rate of an organic compound, the rate onset temperature may be in the range of 200 to 255° C. If the rate onset temperature is below 200° C. the evaporation may be too rapid and therefore difficult to control. If the rate onset temperature is above 255° C. the evaporation rate may be too low which may result in low takt time and decomposition of the organic compound in VTE source may occur due to prolonged exposure to elevated temperatures.
The rate onset temperature is an indirect measure of the volatility of a compound. The higher the rate onset temperature the lower is the volatility of a compound.
According to another embodiment the compound of Formula (I) may have a rate onset temperature TRO of about ≥200° C. and about ≤260° C., preferably about ≥220° C. and about ≤260° C., further preferred about ≥220° C. and about ≤260° C., in addition preferred about ≥230° C. and about ≤255° C.
The dipole moment |{right arrow over (μ)}| of a molecule containing N atoms is given by:
where qi and {right arrow over (r)}i are the partial charge and position of atom i in the molecule.
The dipole moment is determined by a semi-empirical molecular orbital method. The geometries of the molecular structures are optimized using the hybrid functional B3LYP with the 6-31G* basis set in the gas phase as implemented in the program package TURBOMOLE V6.5 (TURBOMOLE GmbH, Litzenhardtstrasse 19, 76135 Karlsruhe, Germany). If more than one conformation is viable, the conformation with the lowest total energy may be selected to determine the bond lengths of the molecules.
According to one embodiment the compounds according to Formula (I) may have a dipole moment (Debye) in the range from about ≥0.4 to about ≤4, preferably from about ≥1.3 to about ≤3.8, further preferred from about ≥1.4 to about ≤3.6.
The HOMO and LUMO are calculated with the program package TURBOMOLE V6.5. The optimized geometries and the HOMO and LUMO energy levels of the molecular structures are determined by applying the hybrid functional B3LYP with a 6-31G* basis set in the gas phase. If more than one conformation is viable, the conformation with the lowest total energy is selected.
According to one embodiment the compounds according to Formula (I) may have a LUMO energy level (eV) in the range from about −2.20 eV to about −1.50 eV, preferably from about −2.1 eV to about −1.70 eV, further preferred from about −2.08 eV to about −1.90 eV, also preferred from about −2.06 eV to about −1.95 eV.
Surprisingly, it was found that the organic electronic device comprising first organic semiconductor layer and second organic semiconductor layer according to the present invention solve the problem underlying the present invention by being superior over the organic electronic device known in the art, in particular with respect to operating voltage, which is important for reducing power consumption and increasing battery life, for example of a mobile display device. At the same time the cd/A efficiency, also referred to as current efficiency is kept at a similar or even improved level. Long life time at high current density is important for the longevity of a device which is run at high brightness.
Likewise, some compounds falling within the scope of the broadest definition of the present invention have surprisingly be found to be particularly well performing with respect to the mentioned property of glass transition temperature, rate onset temperature and/or operating voltage in organic electronic devices. These compounds are discussed herein to be particularly preferred.
The beneficial effect of the invention on the performance of organic electronic devices can be seen in Table 3 and Table 4.
Anode A material for the anode may be a metal or a metal oxide, or an organic material, preferably a material with work function above about 4.8 eV, more preferably above about 5.1 eV, most preferably above about 5.3 eV. Preferred metals are noble metals like Pt, Au or Ag, preferred metal oxides are transparent metal oxides like ITO or IZO which may be advantageously used in bottom-emitting OLEDs having a reflective cathode.
In devices comprising a transparent metal oxide anode or a reflective metal anode, the anode may have a thickness from about 50 nm to about 100 nm, whereas semitransparent metal anodes may be as thin as from about 5 nm to about 15 nm, and non-transparent metal anodes may have a thickness from about 15 nm to about 150 nm.
The hole injection layer may improve interface properties between the anode and an organic material used for the hole transport layer, and is applied on a non-planarized anode and thus may planarize the surface of the anode. For example, the hole injection layer may include a material having a median value of the energy level of its highest occupied molecular orbital (HOMO) between the work function of the anode material and the energy level of the HOMO of the hole transport layer, in order to adjust a difference between the work function of the anode and the energy level of the HOMO of the hole transport layer.
When the hole transport region comprises a hole injection layer, the hole injection layer may be formed on the anode by any of a variety of methods, for example, vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, or the like.
When hole injection layer is formed using vacuum deposition, vacuum deposition conditions may vary depending on the material that is used to form the hole injection layer, and the desired structure and thermal properties of the hole injection layer to be formed and for example, vacuum deposition may be performed at a temperature of about 100° C. to about 500° C., a pressure of about 10−6 Pa to about 10−1 Pa, and a deposition rate of about 0.1 to about 10 nm/sec, but the deposition conditions are not limited thereto.
When the hole injection layer is formed using spin coating, the coating conditions may vary depending on the material that is used to form the hole injection layer, and the desired structure and thermal properties of the hole injection layer to be formed. For example, the coating rate may be in the range of about 2000 rpm to about 5000 rpm, and a temperature at which heat treatment is performed to remove a solvent after coating may be in a range of about 80° C. to about 200° C., but the coating conditions are not limited thereto.
According to another embodiment the hole injection layer comprises at least one radialene compound, wherein the radialene compound is a [3]-radialene, and preferably the radialene compound is a [3]-radialene and selected from the group A1 to A21
The hole injection layer may further comprise a p-dopant to improve conductivity and/or hole injection from the anode.
p-Dopant
In another aspect, the p-dopant may be homogeneously dispersed in the hole injection layer.
In another aspect, the p-dopant may be present in the hole injection layer in a higher concentration closer to the anode and in a lower concentration closer to the cathode.
The p-dopant may be one of a quinone derivative or a radialene compound but not limited thereto. Non-limiting examples of the p-dopant are quinone derivatives such as tetracyanoquinonedimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ), 4,4′, 4″-((1E,1′E,1″E)-cyclopropane-1,2,3-triylidenetris(cyanomethanylylidene))-tris(2,3,5,6-tetrafluorobenzonitrile).
According to another embodiment, an organic electronic device comprising a first organic semiconductor layer comprising a composition according to invention may additional comprise a layer comprising a radialene compound and/or a quinodimethane compound.
In another embodiment, the radialene compound and/or the quinodimethane compound may be substituted with one or more halogen atoms and/or with one or more electron withdrawing groups. Electron withdrawing groups can be selected from nitrile groups, halogenated alkyl groups, alternatively from perhalogenated alkyl groups, alternatively from perfluorinated alkyl groups. Other examples of electron withdrawing groups may be acyl, sulfonyl groups or phosphoryl groups.
Alternatively, acyl groups, sulfonyl groups and/or phosphoryl groups may comprise halogenated and/or perhalogenated hydrocarbyl. In one embodiment, the perhalogenated hydrocarbyl may be a perfluorinated hydrocarbyl. Examples of a perfluorinated hydrocarbyl can be perfluormethyl, perfluorethyl, perfluorpropyl, perfluorisopropyl, perfluorobutyl, perfluorophenyl, perfluorotolyl; examples of sulfonyl groups comprising a halogenated hydrocarbyl may be trifluoromethylsulfonyl, pentafluoroethylsulfonyl, pentafluorophenylsulfonyl, heptafluoropropylsufonyl, nonafluorobutylsulfonyl, and like.
In one embodiment, the radialene and/or the quinodimethane compound may be comprised in a hole injection, hole transporting and/or a hole generation layer.
In one embodiment, the radialene compound may have formula (XX) and/or the quinodimethane compound may have formula (XXIa) or (XXIb):
wherein R1″, R2″, R3″, R4″, R5″, R6, R7, R8, R11, R12, R15, R16, R20, R21 may be independently selected from an electron withdrawing groups and R9, R10, R13, R14, R17, R18, R19, R22, R3 and R24 may be independently selected from H, halogen and electron withdrawing groups. Electron withdrawing group/s that can be suitable used are above mentioned.
Conditions for forming the hole transport layer and the electron blocking layer may be defined based on the above-described formation conditions for the hole injection layer.
A thickness of the hole transport part of the charge transport region may be from about 10 nm to about 1000 nm, for example, about 10 nm to about 100 nm. When the hole transport part of the charge transport region comprises the hole injection layer and the hole transport layer, a thickness of the hole injection layer may be from about 10 nm to about 1000 nm, for example about 10 nm to about 100 nm and a thickness of the hole transport layer may be from about 5 nm to about 200 nm, for example about 10 nm to about 150 nm. When the thicknesses of the hole transport part of the charge transport region, the HIL, and the HTL are within these ranges, satisfactory hole transport characteristics may be obtained without a substantial increase in operating voltage.
Hole transport matrix materials used in the hole transport region are not particularly limited. Preferred are covalent compounds comprising a conjugated system of at least 6 delocalized electrons, preferably organic compounds comprising at least one aromatic ring, more preferably organic compounds comprising at least two aromatic rings, even more preferably organic compounds comprising at least three aromatic rings, most preferably organic compounds comprising at least four aromatic rings. Typical examples of hole transport matrix materials which are widely used in hole transport layers are polycyclic aromatic hydrocarbons, triarylene amine compounds and heterocyclic aromatic compounds. Suitable ranges of frontier orbital energy levels of hole transport matrices useful in various layer of the hole transport region are well-known. In terms of the redox potential of the redox couple HTL matrix/cation radical of the HTL matrix, the preferred values (if measured for example by cyclic voltammetry against ferrocene/ferrocenium redox couple as reference) may be in the range 0.0-1.0 V, more preferably in the range 0.2-0.7 V, even more preferably in the range 0.3-0.5 V.
The hole transport part of the charge transport region may further include a buffer layer.
Buffer layer that can be suitable used are disclosed in U.S. Pat. Nos. 6,140,763, 6,614,176 and in US2016/248022.
The buffer layer may compensate for an optical resonance distance of light according to a wavelength of the light emitted from the EML, and thus may increase efficiency.
The emission layer may be formed on the hole transport region by using vacuum deposition, spin coating, casting, LB method, or the like. When the emission layer is formed using vacuum deposition or spin coating, the conditions for deposition and coating may be similar to those for the formation of the hole injection layer, though the conditions for the deposition and coating may vary depending on the material that is used to form the emission layer. The emission layer may include an emitter host (EML host) and an emitter dopant (further only emitter).
A thickness of the emission layer may be about 100 Å to about 1000 Å, for example about 200 Å to about 600 Å. When the thickness of the emission layer is within these ranges, the emission layer may have improved emission characteristics without a substantial increase in operating voltage.
According to another embodiment, the emission layer may comprise compound of Formula (I) as emitter host.
The emitter host compound has at least three aromatic rings, which may be independently selected from carbocyclic rings and heterocyclic rings.
Other compounds that can be used as the emitter host is an anthracene matrix compound represented by formula 400 below:
In formula 400, Ar111 and Ar112 may be each independently a substituted or unsubstituted C6-C60 arylene group; Ar113 to Ar116 may be each independently a substituted or unsubstituted C1-C10 alkyl group or a substituted or unsubstituted C6-C60 arylene group; and g, h, i, and j may be each independently an integer from 0 to 4.
In some embodiments, Ar111 and Ar112 in formula 400 may be each independently one of a phenylene group, a naphthalene group, a phenanthrenylene group, or a pyrenylene group; or
a phenylene group, a naphthalene group, a phenanthrenylene group, a fluorenyl group, or a pyrenylene group, each substituted with at least one of a phenyl group, a naphthyl group, or an anthryl group.
In formula 400, g, h, i, and j may be each independently an integer of 0, 1, or 2.
In formula 400, Ar113 to Ar116 may be each independently one of
or
Wherein in the formulas 7 and 8, X may be selected form an oxygen atom and a sulfur atom, but embodiments of the invention are not limited thereto.
In the formula 7, any one of R11 to R14 is used for bonding to Ar111, R11 to R14 that are not used for bonding to Ar111 and R15 to R20 are the same as R1 to R8.
In the formula 8, any one of R21 to R24 is used for bonding to Ar111, R21 to R24 that are not used for bonding to Ar111 and R25 to R30 are the same as R1 to R8.
Preferably, the EML host comprises between one and three heteroatoms selected from the group consisting of N, O or S. More preferred the EML host comprises one heteroatom selected from S or O.
The dopant is mixed in a small amount to cause light emission, and may be generally a material such as a metal complex that emits light by multiple excitation into a triplet or more. The dopant may be, for example an inorganic, organic, or organic/inorganic compound, and one or more kinds thereof may be used.
The emitter may be a red, green, or blue emitter.
The dopant may be a fluorescent dopant, for example ter-fluorene, the structures are shown below. 4.4′-bis(4-diphenyl amiostyryl)biphenyl (DPAVBI, 2,5,8,11-tetra-tert-butyl perylene (TBPe), and Compound 8 below are examples of fluorescent blue dopants.
The dopant may be a phosphorescent dopant, and examples of the phosphorescent dopant may be an organic metal compound comprising Ir, Pt, Os, Ti, Zr, Hf, Eu, Tb, Tm, Fe, Co, Ni, Ru, Rh, Pd, or a combination thereof. The phosphorescent dopant may be, for example a compound represented by formula Z, but is not limited thereto:
J2MX (Z).
In formula Z, M is a metal, and J and X are the same or different, and are a ligand to form a complex compound with M.
The M may be, for example Ir, Pt, Os, Ti, Zr, Hf, Eu, Tb, Tm, Fe, Co, Ni, Ru, Rh, Pd or a combination thereof, and the J and X may be, for example a bidendate ligand.
One or more emission layers may be arranged between the anode and the cathode. To increase overall performance, two or more emission layers may be present.
A charge generation layer (also named CGL) may be arranged between the first and the second emission layer, and second and third emission layer, if present. Typically, the CGL comprises an n-type charge generation layer (also named n-CGL or electron generation layer) and a p-type charge generation layer (also named p-CGL or hole generation layer). An interlayer may be arranged between the n-type CGL and the p-type CGL.
According to another embodiment, the organic semiconductor layer that comprises the compound of Formula (I) and a metal dopant is an n-type charge generation layer. In another embodiment the n-type charge generation layer may consist of the compound of Formula (I) and a metal dopant according to the invention.
In another aspect, the at least n-type charge generation layer may comprise a compound of Formula (I) and a metal dopant, wherein the metal dopant may be a metal selected from Li, Na, Cs, Mg, Ca, Sr, Sm or Yb preferably from Li, Cs, Mg or Yb.
In another aspect, the at least one n-type charge generation layer may comprise a compound of Formula (I) and a metal dopant, wherein the metal dopant may be a metal selected from Li or Yb.
The p-type CGL may comprise at least one radialene compound, wherein the radialene compound is a [3]-radialene, and preferably the radialene compound is a [3]-radialene and selected from the group A1 to A21.
In another aspect, the at least one n-type charge generation layer may consist of a compound of Formula (I) and a metal dopant, wherein the metal dopant may be selected from Li or Yb.
According to another embodiment, the organic semiconductor layer that comprises the compound of Formula (I) and a metal dopant is an electron transport layer. In another embodiment the electron transport layer may consist of the compound of Formula (I) and a metal dopant according to the invention.
In another embodiment, the organic electronic device comprises an electron transport region of a stack of organic layers formed by two or more electron transport layers, wherein at least one electron transport layer comprises the compound of Formula (I) and a metal dopant according to the present invention.
In another aspect, the at least one electron transport layer may comprise a compound of Formula (I) and a metal dopant, wherein the metal dopant may be a metal selected from Li, Na, Cs, Mg, Ca, Sr, Sm or Yb preferably from Li, Cs, Mg or Yb.
In another aspect, the at least one electron transport layer may comprise a compound of Formula (I) and a metal dopant, wherein the metal dopant may be a metal selected from Li or Yb.
In another embodiment, the organic electronic device comprises an electron transport region of a stack of organic layers formed by two or more electron transport layers, wherein at least one electron transport layer may consist of the compound of Formula (I) and a metal dopant according to the present invention.
In another aspect, the at least one electron transport layer may consist of a compound of Formula (I) and a metal dopant, wherein the metal dopant may be a metal selected from Li or Yb.
The thickness of the electron transport layer may be from about 0.5 nm to about 100 nm, for example about 2 nm to about 40 nm. When the thickness of the electron transport layer is within these ranges, the electron transport layer may have improved electron transport ability without a substantial increase in operating voltage.
According to another aspect of the invention, the organic electronic device may further comprise an electron injection layer between the electron transport layer (first-ETL) and the cathode.
The electron injection layer (EIL) may facilitate injection of electrons from the cathode.
According to another aspect of the invention, the electron injection layer may comprise:
The electron injection layer may include at least one selected from LiF, NaCl, CsF, Li2O, and BaO.
A thickness of the EIL may be from about 0.1 nm to about 10 nm, or about 0.3 nm to about 9 nm. When the thickness of the electron injection layer is within these ranges, the electron injection layer may have satisfactory electron injection ability without a substantial increase in operating voltage.
The electron injection layer may comprise or consist of the compound of Formula (I) and a metal dopant according to the invention.
A material for the cathode may be a metal, an alloy, or an electrically conductive compound that have a low work function, or a combination thereof. Specific examples of the material for the cathode may be lithium (Li), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), silver (Ag) etc. In order to manufacture a top-emission light-emitting device having a reflective anode deposited on a substrate, the cathode may be formed as a light-transmissive electrode from, for example, indium tin oxide (ITO), indium zinc oxide (IZO) or silver (Ag).
In devices comprising a transparent metal oxide cathode or a reflective metal cathode, the cathode may have a thickness from about 50 nm to about 100 nm, whereas semitransparent metal cathodes may be as thin as from about 5 nm to about 15 nm.
Substrate
A substrate may be further disposed under the anode or on the cathode. The substrate may be a substrate that is used in a general organic light emitting diode and may be a glass substrate or a transparent plastic substrate with strong mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance.
Hereinafter, the embodiments are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following examples.
These and/or other aspects and advantages of the present invention will become apparent and more readily appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings, of which:
Reference will now be made in detail to the exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The exemplary embodiments are described below, in order to explain the aspects of the present invention, by referring to the figures.
Herein, when a first element is referred to as being formed or disposed “on” a second element, the first element can be disposed directly on the second element, or one or more other elements may be disposed there between. When a first element is referred to as being formed or disposed “directly on” a second element, no other elements are disposed there between.
Instead of a single electron transport layer 160, optional an electron transport layer stack (ETL) can be used. The electron transport layer stack (ETL) comprises a first electron transport layer and a second electron transport layer, wherein the first electron transport layer is arranged near to EML and the second electron transport layer is arranged near to the cathode (190). The first and/or the second electron transport layer comprise the compound of Formula (I) and a metal dopant according to the invention.
In the description above the method of manufacture an OLED 100 of the present invention is started with a substrate 110 onto which an anode 120 is formed, on the anode electrode 120, an hole injection layer 130, hole transport layer 140, optional an electron blocking layer 145, an emission layer 150, optional a hole blocking layer 155, at least a first electron transport layer 160 and at least one second electron transport layer 161, optional at least one electron injection layer 180, and a cathode 190 are formed, in that order or the other way around.
Referring to
In the description above the method of manufacture an OLED 200 of the present invention is started with a substrate 110 onto which an anode 120 is formed, on the anode electrode 120, a first hole injection layer 130, first hole transport layer 140, optional a first electron blocking layer 145, a first emission layer 150, optional a first hole blocking layer 155, optional at least one first electron transport layer 160, an n-type CGL 185, a p-type CGL 135, a second hole transport layer 141, optional a second electron blocking layer 146, a second emission layer 151, an optional second hole blocking layer 156, an at least one second electron transport layer 161, an optional second electron injection layer (EIL) 181 and a cathode 190 are formed, in that order or the other way around.
Hereinafter, the embodiments are illustrated in more detail with reference to examples. However, the present disclosure is not limited to the following examples. Reference will now be made in detail to the exemplary aspects.
To synthesize compound of Formula (I) a flask was flushed with nitrogen and charged with reagent 1 (1.1 equiv.), reagent 2 (1 equiv.), K2CO3 (2 equiv.) dissolved in deaerated water), [1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) (2 mol %). A deaerated mixture of toluene and ethanol (5:1) was added and the reaction mixture was heated to reflux under a nitrogen atmosphere while monitoring with TLC. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed with water (100 mL) and methanol (30 mL). For further purification the crude product was then dissolved in dichloromethane and filtered through a pad of silica gel. After rinsing with additional dichloromethane, the filtrate was concentrated under reduced pressure and precipitated from methanol (150 mL). The resulting precipitate was recrystallized from 100 mL toluene. The formed precipitate was collected by suction filtration and washed with small portion of toluene to give compound of Formula (I). An additional crop is isolated by precipitation by concentration of the toluene mother liquor Final purification was achieved by sublimation.
To synthesize compound of Formula (I) a flask was flushed with nitrogen and charged with reagent (1) (1.1 equiv.), 4′-chloro-2,2′:6′, 2″-terpyridine (2) 1 equiv.), K2CO3 (2 equiv. dissolved in deaerated water), [1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) (2 mol %). A deaerated mixture of toluene and ethanol (5:1) was added and the reaction mixture was heated to reflux under a nitrogen atmosphere while monitoring with TLC. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed with water (100 mL) and methanol (30 mL). For further purification the crude product was then dissolved in dichloromethane and filtered through a pad of silica gel. After rinsing with additional dichloromethane, the filtrate was concentrated under reduced pressure and precipitated from methanol (150 mL). The resulting precipitate was recrystallized from 100 mL toluene. The formed precipitate was collected by suction filtration and washed with small portion of toluene to give compound of Formula (I). An additional crop is isolated by precipitation by concentration of the toluene mother liquor Final purification was achieved by sublimation.
To synthesize compound of Formula (I) a flask was flushed with nitrogen and charged with reagent (1) (1.1 equiv.), Reagent 2 (1 equiv.), K2CO3 (2 equiv.) dissolved in deaerated water), [1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) (2 mol %). A deaerated mixture of toluene and ethanol (5:1) was added and the reaction mixture was heated to reflux under a nitrogen atmosphere while monitoring with TLC. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed with water (100 mL) and methanol (30 mL). For further purification the crude product was then dissolved in dichloromethane and filtered through a pad of silica gel. After rinsing with additional dichloromethane, the filtrate was concentrated under reduced pressure and precipitated from methanol (150 mL). The resulting precipitate was recrystallized from 100 mL toluene. The formed precipitate was collected by suction filtration and washed with small portion of toluene to give compound of Formula (I). An additional crop is isolated by precipitation by concentration of the toluene mother liquor Final purification was achieved by sublimation.
To synthesize compound of Formula (I) a flask was flushed with nitrogen and charged with reagent (1) (1.1 equiv.), Reagent 2 (1 equiv.), K2CO3 (2 equiv.) dissolved in deaerated water), [1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) (2 mol %). A deaerated mixture of toluene and ethanol (5:1) was added and the reaction mixture was heated to reflux under a nitrogen atmosphere while monitoring with TLC. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed with water (100 mL) and methanol (30 mL). For further purification the crude product was then dissolved in dichloromethane and filtered through a pad of silica gel. After rinsing with additional dichloromethane, the filtrate was concentrated under reduced pressure and precipitated from methanol (150 mL). The resulting precipitate was recrystallized from 100 mL toluene. The formed precipitate was collected by suction filtration and washed with small portion of toluene to give compound of Formula (I). An additional crop is isolated by precipitation by concentration of the toluene mother liquor Final purification was achieved by sublimation.
To synthesize 7-(3-([2,2′-bipyridin]-6-yl)phenyl)dibenzo[c,h]acridine (compound 1) a flask was flushed with nitrogen and charged with 7-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)dibenzo[c,h]acridine (30 g, 62.3 mmol), 6-bromo-2,2′-bipyridine (16.1 g, 68.5 mmol), K3PO4 (31.8 g, 150 mmol, dissolved in 75 mL deaerated water), chloro(crotyl)(2-dicyclohexylphosphino-2′, 6′-dimethoxybiphenyl)palladium(II) (0.76 g, 1.24 mmol). Deaerated THF (310 mL) was added and the reaction mixture was heated to 60° C. under a nitrogen atmosphere while monitoring with TLC. After cooling down to room temperature the solvent was distilled of. The resulting solid was extracted with CHCl3/H2O. The CHCl3 solution was dried over MgSO4 and filtered through a pad of florisil, additional rinsing is done with THF. The THF-solution is concentrated under reduced pressure. The precipitate is collected by suction filtration. After drying 12.5 g of MX1 were obtained. Final purification was achieved by sublimation. HPLC 100%; m/z=510.2 ([M+H]+).
A flask was flushed with nitrogen and charged with 2-(4-bromophenyl)-3,5,6-triphenylpyrazine (15.0 g, 32.4 mmol), bis(pinacolato)diboron (9.04 g, 35.6 mmol), Pd(dppf)Cl2 (0.71 g, 0.97 mmol), and potassium acetate (9.5 g, 97.2 mmol). Dry and deaerated DMF (90 mL) was added and the reaction mixture was heated to 100° C. under a nitrogen atmosphere overnight. Subsequently, all volatiles were removed in vacuo, water (400 mL) and dichloromethane (1 L) were added and the organic phase was washed with water (3×400 mL). After drying over MgSO4, the organic phase was filtered through a pad of silica gel. After rinsing with additional dichloromethane (1 L), the filtrate was concentrated under reduced pressure to a minimal volume. Methanol (350 mL) was added and the suspension was left stirring at room temperature overnight. The solid was collected by suction filtration to yield 15.9 g (96%) of 2,3,5-triphenyl-6-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyrazine after drying.
A flask was charged with 1-(3-bromophenyl)-2-phenylethane-1,2-dione (36.6 g, 126.5 mmol), 1,2-diphenylethane-1,2-diamine (38.7 g, 182.1 mmol), and acetic acid (320) mL. The mixture was heated to 75° C. for 24 h. Subsequently, the reaction mixture was concentrated under reduced pressure to approx. 100 mL and then carefully poured into sat. aq. K2CO3 (700 mL). After extraction with dichloromethane three times, the combined organic phases were washed with brine, dried over MgSO4, and concentrated under reduced pressure. The crude product was purified by column chromatography (silica, n-hexane/dichloromethane 8:2) and trituration with n-hexane to afford 38.8 g (66%) of 2,3,5-triphenyl-6-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyrazine after drying.
To synthesize 4′-(3-(3,5,6-triphenylpyrazin-2-yl)phenyl)-2,2′:6′, 2″-terpyridine (compound G18) a flask was flushed with nitrogen and charged with 2,3,5-triphenyl-6-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)pyrazine (1) (17.0 g, 33.0 mmol), 4′-chloro-2,2′:6′, 2″-terpyridine (2) (8.1 g, 30.0 mmol), K2CO3 (8.29 g, 60 mmol, dissolved in 30 mL deaerated water), [1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium(II) (0.44 g, 0.6 mmol). A deaerated mixture of toluene and ethanol (5:1, 180 mL) was added and the reaction mixture was heated to reflux under a nitrogen atmosphere while monitoring with TLC. After cooling down to room temperature, the resulting precipitate was isolated by suction filtration and washed with water (100 mL) and methanol (30 mL). For further purification the crude product was then dissolved in dichloromethane and filtered through a pad of silicagel. After rinsing with additional dichloromethane, the filtrate was concentrated under reduced pressure and precipitated from methanol (150 mL). The resulting precipitate was recrystallized from 100 mL toluene. The formed precipitate was collected by suction filtration and washed with small portion of toluene to give 7.8 g of compound 1. An additional crop is isolated by precipitation by concentration of the toluene mother liquor. Combined 11.6 g of Compound MX2 were obtained after drying. Final purification was achieved by sublimation. HPLC: 99.96%, m/z=616 ([M+H]+).
Further examples such as compounds G1 to G3, G12, G36 and G37 were obtained by following this exemplary protocol, varying reagent 1, using the reagents and conditions and purification adaption as given in the Table 1 and in Table 2 the properties of inventive compounds of Formula (I) are listed.
Compounds Used in p-CGL
For bottom emission devices, Examples 1 to 4 and comparative examples 1 to 2, a glass substrate was cut to a size of 150 mm×150 mm×0.7 mm, ultrasonically cleaned with isopropyl alcohol for 5 minutes and then with pure water for 5 minutes, and cleaned again with UV ozone for 30 minutes, to prepare a first electrode. 90 nm ITO were deposited on the glass substrate at a pressure of 10−5 to 10−7 mbar to form the anode.
Then, Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine (CAS 1242056-42-3) with 2,2′,2″-(cyclopropane-1,2,3-triylidene)tris(2-(p-cyanotetrafluorophenyl)acetonitrile) (A2) was vacuum deposited on the anode, to form a HIL having a thickness of 10 nm according to inventive Example 1-4. In comparative Example 1-2 HIL is formed in the same was as in inventive example accept HAT-CN was used instead of A2 (Table 3).
Then, Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl) phenyl]-amine was vacuum deposited on the HIL, to form a HTL having a thickness of 128 nm.
Then N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1′:4′,1″-terphenyl]-4-amine (CAS 1198399-61-9) was vacuum deposited on the HTL, to form an electron blocking layer (EBL) having a thickness of 5 nm.
Then 97 vol.-% H09 (Sun Fine Chemicals, South Korea) as EML host and 3 vol.-% BD200 (Sun Fine Chemicals, South Korea) as fluorescent blue dopant were deposited on the EBL, to form a blue-emitting EML with a thickness of 20 nm.
Then the hole blocking layer is formed with a thickness of 5 nm by depositing 2-(3′-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine on the emission layer.
Then, the first electron transporting layer is formed on the hole blocking layer according to Examples 1 to 4 and comparative examples 1 to 2 with a thickness of 31 nm. The electron transport layer may comprise 99 wt.-% matrix compound of Formula 1 and 1 wt.-% of Li as metal dopant or electron transport layer may comprise 97 wt.-% matrix compound of Formula 1 and 3 wt.-% of Yb, see Table 3.
Al is evaporated at a rate of 0.01 to 1 Å/s at 10−7 mbar to form a cathode with a thickness of 100 nm.
The OLED stack is protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed, which includes a getter material for further protection.
For bottom emission devices, Examples 5 to 10 and comparative examples 3 to 5, a glass substrate was cut to a size of 150 mm×150 mm×0.7 mm, ultrasonically cleaned with isopropyl alcohol for 5 minutes and then with pure water for 5 minutes, and cleaned again with UV ozone for 30 minutes, to prepare a first electrode. 90 nm ITO were deposited on the glass substrate at a pressure of 10−5 to 10−7 mbar to form the anode.
Then, 97 vol.-% Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine (CAS 1242056-42-3) with 3 vol.-% 2,2′,2″-(cyclopropane-1,2,3-triylidene)tris(2-(p-cyanotetrafluorophenyl)acetonitrile) (A2) was vacuum deposited on the anode, to form a HIL having a thickness of 10 nm according to the inventive Example 5-10 and comparative Example 3-4 (Table 4).
Then, Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl) phenyl]-amine was vacuum deposited on the HIL, to form a first HTL having a thickness of 128 nm.
Then N,N-bis(4-(dibenzo[b,d]furan-4-yl)phenyl)-[1,1′:4′,1″-terphenyl]-4-amine (CAS 1198399-61-9) was vacuum deposited on the HTL, to form an electron blocking layer (EBL) having a thickness of 5 nm.
Then 97 vol.-% H09 (Sun Fine Chemicals, South Korea) as EML host and 3 vol.-% BD200 (Sun Fine Chemicals, South Korea) as fluorescent blue dopant were deposited on the EBL, to form a first blue-emitting EML with a thickness of 20 nm.
Then the first hole blocking layer is formed with a thickness of 5 nm by depositing 2-(3′-(9,9-dimethyl-9H-fluoren-2-yl)-[1,1′-biphenyl]-3-yl)-4,6-diphenyl-1,3,5-triazine on the emission layer.
Then, the electron transporting layer having a thickness of 25 nm is formed on the hole blocking layer by depositing 4′-(4-(4-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl)naphthalen-1-yl)-[1,1′-biphenyl]-4-carbonitrile. The electron transport layer (ETL) comprises 50 wt.-% matrix compound and 50 wt.-% of LiQ.
Then the n-CGL was formed on ETL with a thickness of 15 nm. The n-CGL comprises 99 wt.-% matrix compound of Formula 1 and 1 wt.-% of Li as metal dopant or electron transport layer may comprise 97 wt.-% matrix compound of Formula 1 and 3 wt.-% of Yb, see Table 4. Then the p-CGL was formed on n-CGL with a thickness of 10 nm on n-CGL by depositing Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]-amine (CAS 1242056-42-3) with 2,2′,2″-(cyclopropane-1,2,3-triylidene)tris(2-(p-cyanotetrafluorophenyl)acetonitrile) (A2) according the inventive example 5-10. (Table 4). In comparative example p-CGL was formed on n-CGL in the same way as in inventive examples accept that HAT-CN was used instead of A2.
Then, Biphenyl-4-yl(9,9-diphenyl-9H-fluoren-2-yl)-[4-(9-phenyl-9H-carbazol-3-yl) phenyl]-amine was vacuum deposited on the p-CGL, to form a second HTL having a thickness of 10 nm.
Al is evaporated at a rate of 0.01 to 1 Å/s at 10−7 mbar to form a cathode with a thickness of 100 nm.
The OLED stack is protected from ambient conditions by encapsulation of the device with a glass slide. Thereby, a cavity is formed, which includes a getter material for further protection.
To assess the performance of the inventive examples compared to the prior art, the current efficiency is measured at 20° C. The current-voltage characteristic is determined using a Keithley 2635 source measure unit, by sourcing a voltage in V and measuring the current in mA flowing through the device under test. The voltage applied to the device is varied in steps of 0.1V in the range between 0V and 10V. Likewise, the luminance-voltage characteristics and CIE coordinates are determined by measuring the luminance in cd/m2 using an Instrument Systems CAS-140CT array spectrometer (calibrated by Deutsche Akkreditierungsstelle (DAkkS)) for each of the voltage values. The cd/A efficiency at 10 mA/cm2 is determined by interpolating the luminance-voltage and current-voltage characteristics, respectively.
Lifetime LT of the device is measured at ambient conditions (20° C.) and 30 mA/cm2, using a Keithley 2400 source meter, and recorded in hours.
The brightness of the device is measured using a calibrated photo diode. The lifetime LT is defined as the time till the brightness of the device is reduced to 97% of its initial value.
Therefore, it can be seen the material for ETL (Example 1-4) and n-CGL (Example 5-8) can secure low driving voltage and high efficiency of an organic electronic device, when used in an organic electronic device.
Table 3 shows that the OLED device containing ETL comprising compound of Formula (I) and a metal dopant and HIL comprising of a HTM-1 and A2 as dopant have lower operating voltage (cd/A at 15 mA/cm2) as compared to the OLED device containing ETL comprising of compound of formula 1 and a metal dopant and HIL comprising HAT-CN.
Table 4 shows that the OLED device containing n-CGL comprising compound of Formula (1) and a metal dopant and p-CGL comprising an HTM-1 and A2 have lower operating voltage (cd/A at 15 mA/cm2) as compared to the OLED device containing n-CGL comprising compound of formula 1 and a metal dopant and comprising p-CGL comprising of compound of HTM-1 and HAT-CN.
In summary, low operating voltage (cd/A at 15 mA/cm2) and improved lifetime may be achieved when the first organic semiconductor layer may comprise a compound of Formula (I) and metal dopant.
While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Therefore, the aforementioned embodiments should be understood to be exemplary but not limiting the present invention in any way.
| Number | Date | Country | Kind |
|---|---|---|---|
| 19199928.3 | Sep 2019 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2020/076945 | 9/24/2020 | WO |
