This is a National Stage Entry of Application No. PCT/JP2011/080009 filed Dec. 26, 2011, claiming priority based on Japanese Patent Application No. 2010-293101 filed Dec. 28, 2010, the contents of all of which are incorporated herein by reference in their entirety.
The present invention relates to an organic electroluminescent lighting device that includes an organic light emitting film as a light source, and a method for manufacturing the lighting device.
As one of lighting devices, there is known an organic electroluminescent lighting device that includes an organic light emitting film as a light source. In the organic electroluminescent lighting device, the organic light emitting film is sandwiched between a transparent anode film and a cathode film, and emits light when an electric field is generated between the electrodes. The light is transmitted through the anode film to be applied to the outside. For the anode film, a transparent conductive material (or transparent metal oxide) such as ITO (Indium Tin Oxide), ZnO, SnO 2 (Nesa glass) is used. The transparent conductive material (or transparent metal oxide) has relatively large electrical resistivity ρ(Ω·m). Power is generally supplied to the anode film from both of its ends. Accordingly, wring resistance is larger farther from both ends. Since the increase of the wiring resistance is accompanied by the increase of a voltage drop, the voltage is no longer applied uniformly to the entire organic light emitting film. The luminance of the organic light emitting film depends on the voltage. Thus, when the voltage is not applied uniformly to the organic light emitting film, there is a possibility that the luminance of the organic light emitting film will be nonuniform. To reduce the wiring resistance, therefore, there is known a technology of forming auxiliary electrode films whose resistance is lower than the anode film in a lattice shape on the surface of the anode film (JP2004-14128A).
To manufacture organic electroluminescent lighting device 100 shown in
In organic electroluminescent lighting device 100 thus configured, when power is supplied between power supply terminal film 121 and power supply terminal film 131 from a power source, organic light emitting film 114 emits light. At this time, since there are auxiliary electrode films 112 formed on the surface of electrode film 111, wiring resistance is reduced. Thus, the value of a dropping voltage is also reduced. As a result, nonuniformity of luminance in the organic light emitting film can be prevented.
Patent Literature 1: JP20004-14128A
However, in organic electroluminescent lighting device 100 shown in
It is therefore an object of the present invention to provide an organic electroluminescent lighting device in which it is difficult for an organic light emitting film to be scratched, thereby providing a quality guarantee with improved reliability, and a method for manufacturing the lighting device.
To achieve the object, an organic electroluminescent lighting device according to the present invention includes: a transparent substrate; a plurality of transparent first electrode films spaced from each other on the surface of the transparent substrate; auxiliary electrode films arranged between the plurality of first electrode films, having electrical resistivity that is lower than that of the first electrode films, and electrically connected to the plurality of first electrode films; insulating films covering the auxiliary electrode films; power supply terminal films arranged on the surface of the transparent substrate adjacently to an arrangement region in which the plurality of first electrode films and the auxiliary electrode films are arranged, and electrically connected to the plurality of first electrode films and the auxiliary electrode films; an organic light emitting film covering the first electrode films and the insulating films; and a second electrode film covering the organic light emitting film.
To achieve the object, a method for manufacturing an organic electroluminescent lighting device according to the present invention includes: the first step of forming a plurality of transparent first electrode films spaced from each other on the surface of a transparent substrate, auxiliary electrode films arranged between the plurality of first electrode films, having electrical resistivity lower than that of the first electrode films, and electrically connected to the plurality of first electrode films, and power supply terminal films arranged adjacently to an arrangement region in which the plurality of first electrode films and the auxiliary electrode films are arranged, and electrically connected to the plurality of first electrode films and the auxiliary electrode films; the second step of forming insulating films covering the auxiliary electrode films; the third step of forming an organic light emitting film covering the first electrode films and the insulating films; and the fourth step of forming a second electrode film covering the organic light emitting film.
According to the present invention, the auxiliary electrode film covered with the insulating film is formed not on the surface of the first electrode film but between the first electrode films. Accordingly, auxiliary electrode film has a portion which protrudes from the first electrode film and the height of the portion is lower than the structure of the auxiliary electrode film formed on the surface of the first electrode film. This makes it difficult for the organic light emitting film, to be scratched, thus improving the reliability of quality guarantee. Employing this configuration or structure can provide the aforementioned effect without increasing the number of steps or process loads and without changing manufacturing costs.
(First Embodiment)
Organic electroluminescent lighting device 10 according to the embodiment includes, for example, a plurality of first rectangular electrode films 2, auxiliary electrode films 3, power supply terminal films 4, and power supply terminal films 5 (other power supply terminal films) formed on the surface of alkali-free glass transparent substrate 1.
First electrode film 2, which is an anode, is made of a transparent conductive material (or transparent metal oxide) (e.g., ITO). First electrode films 2 are spaced from each other in a matrix on the surface of transparent substrate 1.
Auxiliary electrode film 3 is made of a metallic material such as Al (aluminum), Cr (chromium), Mo (molybdenum), Mo—Nb (molybdenum-niobium alloy), or Al—Nd (aluminum-neodymium alloy) having electrical resistivity ρ(Ω·m) lower than that that of first electrode film 2. Auxiliary electrode films 3 are arranged between first electrode films 2 in a lattice shape. The surfaces of auxiliary electrode films 3 are covered with insulating films 6. The surfaces of insulating films 6, which have tapered ends, are round.
Power supply terminal 4 is formed adjacently to arrangement region 11 where first electrode film 2 and auxiliary electrode film 3 are arranged. Power supply terminal 5 is formed away from first electrode film 2 and power supply terminal film 4. Power supply terminal 5 is made of a transparent conductive material (or transparent metal oxide) as in the case of first electrode film 2.
First electrode film 2 and insulating film 6 are covered with organic light emitting film 7. Organic light emitting film 7 includes a light emitting layer (not shown) and two transport layers (not shown) sandwiching the light emitting layer.
The surface of organic light emitting film 7 and power supply terminal film 5 are covered with second electrode film 8. More specifically, second electrode film 8 is smaller than organic light emitting film 7 with respect to the side of power supply terminal film 4, and does not need to cover power supply terminal film 5 as long as it makes contact with power supply terminal film 5 with respect to the side of power supply terminal film 5. Second electrode film 8, which is a cathode, is made of a metallic material such as Al or Ag.
In organic electroluminescent lighting device 10 thus configured, when voltage is applied between power supply terminal film 4 and power supply terminal film 5 from a power source, an electric field is generated between first electrode film 2 and second electrode film 8. Accordingly, organic light emitting film 7 emits light. The light is transmitted through first electrode film 2 to be applied to the outside. Referring to
First, through a sputtering process using a shadow mask, a plurality of first electrode films 2 and power supply terminal films 4 and 5 are formed on the surface of transparent substrate 1 (refer to
Then, auxiliary electrode films 3 are formed in a lattice shape between the plurality of first electrode films 2 (refer to
Then, insulating film 6 is formed on the surface of auxiliary electrode film 3 by depositing a photoresist (refer to
Then, organic light emitting film 7 is formed by vacuum deposition using the shadow mask to cover the surface of first electrode film 2 and the surface of insulating film 6 (refer to
Lastly, second electrode film 8 is formed to cover the surface of organic light emitting film 7 and power supply terminal film 5 (refer to
According to organic electroluminescent lighting device 10 of the embodiment thus manufactured, auxiliary electrode film 3 is formed not on the surface of first electrode film 2 but between first electrode films 2. Accordingly, auxiliary electrode film 3 which is covered with insulating film 6 has a portion which protrudes from first electrode film 2 and the height of the portion is lower than the structure of auxiliary electrode film 3 formed on the surface of first electrode film 2. This makes it difficult for organic light emitting film 7 to be scratched. As a result, reliability can be improved by preventing unlighting caused by short-circuiting during lighting of the organic electroluminescent lighting device. In the embodiment, auxiliary electrode film 3 is thinner than first electrode film 2. However, auxiliary electrode film 3 can be thicker than first electrode film 2.
According to organic electroluminescent lighting device 10 of the embodiment, the device has an island structure in which the transparent electrode film whose electrical resistivity is relatively larger consists of the plurality of first electrode films 2 are apart from each other, and each first electrode film 2 is surrounded with auxiliary electrode film 3 lower in electrical resistivity than first electrode film 2. Accordingly, because the length of the transparent electrode film contributing to wiring resistance is smaller and voltage drop is within each first electrode film 2, electronic carriers are uniformly injected into organic light emitting film 7 compared with organic electroluminescent lighting device 100 shown in
(Second Embodiment)
In organic electroluminescent lighting device 10 of the first embodiment, power supply terminal films 4 and 5 are made of the transparent conductive materials (or transparent metal oxides) similar to those of first electrode films 2. On the other hand, in organic electroluminescent lighting device 20 of this embodiment, power supply terminal films 4 and 5 are made of metallic materials similar to those of auxiliary electrode films 3. The metallic material used for auxiliary electrode film 3 has electrical resistivity that is lower than that of a transparent metal oxide used for first electrode film 2. Thus, the resistance of power supply terminal films 4 and 5 is lower than that of the first embodiment. As a result, organic electroluminescent lighting device 20 of the embodiment can reduce a driving voltage required to cause organic light emitting film 7 to emit more light than organic electroluminescent lighting device 10 of the first embodiment. Referring to
First, as in the case of the first embodiment, a plurality of first electrode films 2 are spaced from each other in a matrix on the surface of transparent substrate 1 (refer to
Then, auxiliary electrode films 3 are formed between first electrode films 2 in a lattice shape, and power supply terminal films 4 and 5 are formed by using metallic materials similar to those of auxiliary electrode films 3, such as Al (aluminum), Cr (chromium), Mo (molybdenum), Mo—Nb (molybdenum-niobium alloy), or Al—Nd (aluminum-neodymium alloy) (refer to
Then, insulating film 6 is formed by depositing a photoresist on the surface of auxiliary electrode film 3. Photoresist 9 is also deposited on the peripheral edge portion of arrangement region 11 where the plurality of first electrode films 2 and auxiliary electrode films 3 are arranged. Photoresists can be deposited between first electrode film 2 and power supply terminal film 5 and between power supply terminal film 4 and power supply terminal film 5 (refer to
Then, organic light emitting film 7 is formed to cover first electrode films 2 and insulating films 6 excluding the peripheral edge portion of arrangement region 11 on which photoresist 9 has been deposited (refer to
Lastly, second electrode film 8 is formed to cover the surface of organic light emitting film 7 and power supply terminal film 5 (refer to
(Third Embodiment)
First, as in the case of the first and second embodiments, a plurality of first electrode films 2 are formed on the surface of transparent substrate 1 (refer to
Then, auxiliary electrode films 3 are formed between first electrode films 2 in a lattice shape, and power supply terminal films 4 and 5 are formed by using metallic materials similar to those of auxiliary electrode films 3. In the embodiment, as shown in
Then, insulating film 6 is formed by depositing a photoresist on the surface of auxiliary electrode film 3. Photoresist 9 is also deposited on the peripheral edge portion of arrangement region 11. Further, photoresist 9 is deposited on the surface of power supply terminal film 4 excluding the leading end of protruded portion 42 (refer to
Then, organic light emitting film 7 is formed to cover first electrode films 2 and insulating films 6 so that it can make contact with the deposited portion of photoresist 9 (refer to
Lastly, second electrode film 8 is formed to cover or make contact with the surface of organic light emitting film 7 and power supply terminal film 5 (refer to
Hereinafter, the specific Examples of the first to third embodiments will be described.
This Example corresponds to the first embodiment. In organic light emitting film 7 of the Example, Cu—Pc (copper phthalocyanine) is used as a hole injection material. As a hole transport material, α-NPD (N,N′-diphenyl-N—N-bis(1-naphtyl)-1,1′-biophenyl)-4,4′-diamine) is used. For a first light emitting layer, using CBP (4,4′-biscarbazolyl biphenyl) as a host, a material doped with lr (ppy) 3(tris-(2phenylpyridine)iridium complex) and Btp21r (acac) (bis(2-(2′-benzo(4,5-α)thienyl)pyridinate-N,C2′) (acetylacetonate) iridium complex) is used. Further, for a second light emitting layer, using CBP as a host, a material doped with Flr (pic) ((bis(4,6-di-fluorophenyl)-pyridinate-N,C2′) picolinate iridium complex) is used. For a hole block layer, BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) is used. For an electron transport layer, Alq3 is used. LiF is used as an electron injection material. Al is used for a cathode (second electrode film 8).
When the organic electroluminescent lighting device of the Example was lit with driving current set as constant current of 25 A/m2, a driving voltage was 4.8 V, and luminance was 920 cd/m2. Luminance unevenness within the plane of the organic electroluminescent lighting device was 4% at 9 measurement points within the plane based on calculating of (difference between maximum luminance and minimum luminance)/maximum luminance. When the organic electroluminescent lighting device was continuously lit at the aforementioned current density, the lighting was stably continued even after 10000 hours.
This Example corresponds to the second embodiment. In organic light emitting film 7 of the Example, Cu—Pc is used as a hole injection material. As a hole transport material, α-NPD is used. For a first light emitting layer, using CBP as a host, a material doped with lr (ppy) 3 and Btp21r (acac) is used. Further, for a second light emitting layer, using CBP as a host, a material doped with Flr (pic) is used. For a hole block layer, BCP is used. For an electron transport layer, Alq3 is used. LiF is used as an electron injection material. Al is used for a cathode (second electrode film 8).
When the organic electroluminescent lighting device of the Example was lit with driving current set as constant current of 25 A/m2, the driving voltage was 4.6 V, and luminance was 915 cd/m2. Luminance unevenness within the plane of the organic electroluminescent lighting device was 4% at 9 measurement points within the plane based on calculating of (difference between maximum luminance and minimum luminance)/maximum luminance. When the organic EL lighting device was continuously lit at the aforementioned current density, the lighting was stably continued even after 10000 hours.
This Example corresponds to the third embodiment. In organic light emitting film 7 of the Example, Cu—Pc is used as a hole injection material. As a hole transport material, α-NPD is used. For a first light emitting layer, using CBP as a host, a material doped with lr (ppy) 3 and Btp21r (acac) is used. Further, for a second light emitting layer, using CBP as a host, a material doped with Flr (pic) is used. For a hole block layer, BCP is used. For an electron transport layer, Alq3 is used. LiF is used as an electron injection material. Al is used for a cathode (second electrode film 8).
When the organic electroluminescent lighting device of the Example was lit with driving current set as constant current of 25 A/m2, the driving voltage was 4.4 V, and luminance was 920 cd/m2. Luminance unevenness within the plane of the organic electroluminescent lighting device was 3% at 9 measurement points within the plane based on calculating of (difference between maximum luminance and minimum luminance)/maximum luminance. When the organic EL lighting device was continuously lit at the aforementioned current density, the lighting was stably continued even after 10000 hours.
As Comparative Example 1, an organic electroluminescent lighting device related to that of the present invention shown in
As Comparative Example 2, an organic electroluminescent lighting device that did not has an auxiliary electrode film was manufactured, and driven at a current density similar to that described above. As a result, the driving voltage was 5.7 V, and luminance was 790 cd/m2. Luminance unevenness within the plane of the organic electroluminescent lighting device was 30% at 9 measurement points within the plane based on calculating of (difference between maximum luminance and minimum luminance)/maximum luminance. When the organic electroluminescent lighting device was continuously lit under the aforementioned conditions, short-circuiting occurred within 1000 hours, and the organic electroluminescent lighting device was unlit.
Thus, the organic electroluminescent lighting devices according to the Examples 1 to 3 can secure stable lighting for a long time compared with the organic electroluminescent lighting devices of the Comparative Examples 1 and 2.
The embodiments of the present invention have been described. However, the present invention is not limited to the embodiments. Various changes understandable to those skilled in the art can be made of the configuration and the specifics of the present invention.
This application claims priority from Japanese Patent Application No. 2010-293101 filed Dec. 28, 2010, which is hereby incorporated by reference herein in its entirety.
1, 110 Transparent substrate
2 First electrode film
4, 5, 121, 131 Power supply terminal film
6, 113 Insulating film
7, 114 Organic light emitting film
8 Second electrode film
41 Frame portion
42 Protruded portion
10, 20, 100 Organic electroluminescent lighting device
111, 115 Electrode film
Number | Date | Country | Kind |
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2010-293101 | Dec 2010 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2011/080009 | 12/26/2011 | WO | 00 | 5/15/2013 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2012/090903 | 7/5/2012 | WO | A |
Number | Name | Date | Kind |
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20030038591 | Kim | Feb 2003 | A1 |
20080088227 | Lee | Apr 2008 | A1 |
20100176385 | Lifka et al. | Jul 2010 | A1 |
Number | Date | Country |
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2000-231985 | Aug 2000 | JP |
200384683 | Mar 2003 | JP |
2004-014128 | Jan 2004 | JP |
2004-152699 | May 2004 | JP |
2006-278241 | Oct 2006 | JP |
2007-073305 | Mar 2007 | JP |
2008-103305 | May 2008 | JP |
2009-140817 | Jun 2009 | JP |
2010-108851 | May 2010 | JP |
2010-198935 | Sep 2010 | JP |
2010-533355 | Oct 2010 | JP |
Entry |
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International Search Report for PCT/JP2011/080009 dated Feb. 14, 2012. |
Office Action dated May 13, 2014, issued by the Japan Patent Office in corresponding Japanese Application No. 2012-550922. |
Communication dated Aug. 19, 2014, issued by the Japanese Patent Office in counterpart Application No. 2012550922. |
Number | Date | Country | |
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20130234127 A1 | Sep 2013 | US |