The present disclosure relates to a method of manufacturing an organic element, a method of bonding an organic molecular crystal layer, a method of manufacturing a fine linear conductor, an organic element, and a fine linear conductor, and is suitable for use in, for example, various organic elements such as an organic transistor or various fine linear conductors.
An organic molecular crystal is expected to serve as an electronic element such as a thin film transistor (TFT) (see, for example, Non-Patent Document 1), a new superconductor (see, for example, Non-Patent Document 2), or the like. Among various materials, an organic molecular crystal has characteristics that can be formed by vacuum deposition in a low temperature process (see, for example, Non-Patent Document 3), a method without a vacuum process, e.g., applying an organic molecule dissolved in a solvent (see, for example, Non-Patent Document 4), or the like. On the other hand, because the crystalline structure of the organic molecular crystal is affected by the anisotropy of a molecule being a constituent unit, for example, an organic molecular crystal, which has a benzene ring as a skeleton and includes an aromatic compound, has a significant anisotropy. As a result, as seen in pentacene, it often takes a layered structure in a unit of a lamination cycle in a long axial direction of an organic molecule (corresponding to, for example, Lattice Fringes in Non-Patent Document 3). Although the electrogenesis mechanism of the organic molecular crystal having such a layered structure is not completely understood, it is considered that a direction in which pi-orbital overlap is caused among molecules along the layered structure, and a direction perpendicular to the direction have different characteristics. It is considered that in the generation mechanism of superconductivity in the organic molecular crystal, it is important to align the layered structure, from analogy of a copper-oxide superconductor (see, for example, Non-Patent Document 5), to improve the electrical conduction properties. That is, in the case where the organic molecular crystal is used for a device or an electrical lead, it is an important problem to control the crystal orientation. In particular, in the case where an organic molecular crystal including an aromatic compound is formed on a part of a structure that is formed previously, because the size and alignment of the molecule crystal differ depending on the bonding state between the structure and molecules, it is an important problem to control the alignment also in the vicinity of the bonding interface between the electrode and the organic molecular crystal. However, in the prior technique, mainly alignment with respect to the side of a substrate is controlled, e.g., a self-organizing film is formed on the substrate (see, for example, Non-Patent Document 6). Moreover, although, in the interface between the electrode and the organic molecule, improvement in characteristics by the electron transfer such as a thiol treatment (see, for example, Non-Patent Document 7) is reported, there has been no method to microscopically control the alignment at the electrode edge.
Moreover, it is considered that a portion of the electrode and a portion of the insulating film have different conditions of adsorption of the organic molecule, and that many defects occur in the vicinity of the interface, which is a cause of degradation of device characteristics (see, for example, Non-Patent Document 8). As described above, in the prior art, although macroscopic alignment control with respect to the substrate is achieved, microscopic alignment is not controlled in the fine bonding interface with the electrode, in the current situation. Moreover, a practical superconductor mainly includes borides, copper oxides, or metals. Because the technique for processing the superconductor or technique for combining the superconductor with a stabilizing material (see, for example, Patent Document 9) undergoes the high-temperature process or mechanical high deformation process, it has been difficult to combine the superconductor with a molecular element or bio-element.
As for the fine wire using an organic molecule, although a method of manufacturing a fullerene fine wire (see, for example, Patent Document 1) has been known, the method has had a limitation in that two types of solvents are needed and a fullerene is precipitated at the boundary between the solvents.
In view of the above, a problem to be solved by the present disclosure is to provide a method of manufacturing an organic element having favorable characteristics, which is capable of bonding an organic molecular crystal layer to an electrode by controlling the alignment of the organic molecular crystal layer, and to provide an organic element that can be manufactured by using the manufacturing method.
Another problem to be solved by the present disclosure is to provide a method of bonding an organic molecular crystal layer, which is capable of bonding an organic molecular crystal layer to an electrode by controlling the alignment of the organic molecular crystal layer.
Still another problem to be solved by the present disclosure is to provide a method of manufacturing a fine linear conductor having favorable characteristics, which is capable of bonding a fine linear organic molecular crystal layer to a fine linear electrode by controlling the alignment of the organic molecular crystal layer, and to provide a fine linear conductor that can be manufactured by using the manufacturing method.
In order to solve the above-mentioned problem, the present inventors have conducted intensive studies. They have accidentally found that in the process of the study, when an electrode is formed on an insulator, an organic molecular crystal layer including an aromatic compound is formed thereafter, and the organic molecular crystal layer is bonded to the electrode, if an inclined angle of a side surface of the electrode with respect to a surface of the insulator is changed, the alignment of the organic molecular crystal layer with respect to the electrode is changed. Then, based on the findings thus obtained uniquely, they have conducted intensive researches, leading to the present disclosure.
That is, in order to solve the above-mentioned problem, the present disclosure is a method of manufacturing an organic element including controlling alignment of an organic molecular crystal layer with respect to an electrode by controlling an inclined angle of a side surface of the electrode with respect to a main surface of an insulating base, in the case where the electrode and the organic molecular crystal layer are formed on the insulating base, the organic molecular crystal layer including an aromatic compound, the organic molecular crystal layer being bonded to the electrode.
Assuming that the inclined angle of the side surface of the above-mentioned electrode is e, the relationship 0°<θ<90° is established. The entire side surface of the electrode may be flat, or the entire or a part of the side surface may be curved (concave surface, convex surface, or surface having a concave surface portion and a convex surface portion). In the case where the entire or a part of the side surface of the electrode is curved, an average inclined angle of the curved surface is used for θ. The side surface of the electrode may be formed to have a plurality of surfaces having different inclined angles. For example, the side surface of the electrode may be formed to have an upper surface and a lower surface, and the inclined angle of the lower surface may be smaller than that of the upper surface.
The insulating base typically has a flat main surface, and the electrode and the organic molecular crystal layer bonded to the electrode are formed on the main surface. However, a groove may be formed on the main surface of the insulating base, and the electrode and the organic molecular crystal layer may be formed in the groove.
As the insulating base, a fiber-like insulator may be used as necessary. In this case, for example, the electrode and the organic molecular crystal layer are formed so as to have a fine linear shape, on an outer peripheral surface of the fiber-like insulator in a central axial direction of the fiber-like insulator or a direction inclined with respect to the central axial direction.
The organic element may be basically any one as long as an organic molecular crystal layer including an aromatic compound is bonded to an electrode in the organic element. Examples of the organic element include an organic transistor and an organic photoelectric conversion element. In the organic transistor, the organic molecular crystal layer is a semiconductor layer in which a channel is formed, and the electrode to which the organic molecular crystal layer is bonded is a source electrode or a drain electrode. In the organic photoelectric conversion element, the organic molecular crystal layer is an organic photoelectric conversion layer, and the electrode to which the organic molecular crystal layer is bonded is an electrode for drawing current from the organic photoelectric conversion layer, which is provided at one end and the other end thereof. At least a part of the organic molecular crystal layer may be a superconductor. In this case, it is possible to manufacture an organic superconductor element.
The aromatic compound included in the organic molecular crystal layer is classified into a benzenoid aromatic compound, a heteroaromatic compound, and a non-benzenoid benzenoid aromatic compound. Examples of the benzenoid aromatic compound include a condensed ring aromatic compound such as a benzo condensed ring compound. Examples of the heteroaromatic compound include furan, thiophene, pyrrole, and imidazole. Examples of the non-benzenoid benzenoid aromatic compound include annulen, azulene, cyclopentadienyl anion, cycloheptatrienyl cation (tropylium ion), tropone, metallocene, and acepleiadylene.
Among the above-mentioned aromatic compounds, favorably, the condensed-ring compound is used. Examples of the condensed-ring compound include, but not limited to, acenes (naphthalene, anthracene, tetracene, pentacene, etc.), phenanthrene, chrysene, triphenylene, tetraphene, pyrene, picene, pentaphene, perylene, helicene, and coronene. As the aromatic compound, favorably, also a dioxaanthanthrene compound such as 6,12-dioxaanthanthrene (so-called peri-xanthenoxanthene, 6,12-dioxaanthanthrene, which is abbreviated as “PXX” in some cases) is used (see Non-Patent Document 10 and Patent Document 2).
Moreover, the present disclosure is a method of bonding an organic molecular crystal layer including controlling alignment of an organic molecular crystal layer with respect to an electrode by controlling an inclined angle of a side surface of the electrode with respect to a main surface of an insulating base, in the case where the organic molecular crystal layer is bonded to the electrode, the organic molecular crystal layer including an aromatic compound, the electrode being formed on the insulating base.
The description of the above-mentioned method of manufacturing an organic element is applicable to the method of bonding an organic molecular crystal layer unless contrary to the nature thereof.
Moreover, the present disclosure is a method of manufacturing a fine linear conductor, including controlling alignment of a fine linear organic molecular crystal layer with respect to a fine linear electrode by controlling an inclined angle of a side surface of the electrode with respect to a main surface of an insulating base, in the case where the electrode and the organic molecular crystal layer are formed on the insulating base, the organic molecular crystal layer including an aromatic compound, the organic molecular crystal layer being bonded to the electrode.
The description of the above-mentioned method of manufacturing an organic element is applicable to the method of manufacturing a fine linear conductor unless contrary to the nature thereof.
Moreover, the present disclosure is an organic element, including an electrode formed on an insulating base, a side surface of the electrode including a plurality of surfaces having different inclined angles with respect to a main surface of the insulating base, and an organic molecular crystal layer including an aromatic compound, the organic molecular crystal layer being bonded to the electrode, alignment of the organic molecular crystal layer with respect to the electrode being different from each other on the plurality of surfaces.
The description of the above-mentioned method of manufacturing an organic element is applicable to the organic element unless contrary to the nature thereof.
Moreover, the present disclosure is a fine linear conductor, including a fine linear electrode formed on an insulating base, a side surface of the electrode including a plurality of surfaces having different inclined angles with respect to a main surface of the insulating base, and a fine linear organic molecular crystal layer including an aromatic compound, the organic molecular crystal layer being bonded to the electrode, alignment of the organic molecular crystal layer with respect to the electrode being different from each other on the plurality of surfaces.
In the present disclosure described above, because it is possible to control the alignment of organic molecular crystal layer with respect to the electrode while substantially maintaining the layered structure of the organic molecular crystal layer, the organic molecular crystal layer can be formed in the optimal alignment with respect to the electrode while utilizing the original characteristics of the organic molecular crystal layer. Alternatively, it is possible to form a plurality of parts having different alignment on the organic molecular crystal layer.
According to the present disclosure, it is possible to bond an organic molecular crystal layer to an electrode by controlling the alignment of the organic molecular crystal layer, and to obtain an organic element having favorable characteristics.
Moreover, according to the present disclosure, it is possible to bond a fine linear organic molecular crystal layer to a fine linear electrode by controlling the alignment of the organic molecular crystal layer, and to obtain a fine linear conductor having favorable characteristics.
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Hereinafter, a mode for carrying out the invention (hereinafter referred to as “embodiment”) will be described. It should be noted that description will be given in the following order.
1. First Embodiment (method of bonding organic molecular crystal layer)
2. Second Embodiment (method of bonding organic molecular crystal layer)
3. Third Embodiment (method of bonding organic molecular crystal layer)
4. Fourth Embodiment (method of bonding organic molecular crystal layer)
5. Fifth Embodiment (top-gate organic transistor and method of manufacturing the same)
6. Sixth Embodiment (bottom-gate organic transistor and method of manufacturing the same)
7. Seventh Embodiment (fine linear conductor and method of manufacturing the same)
8. Eighth Embodiment (fine linear conductor and method of manufacturing the same)
9. Ninth Embodiment (fine linear conductor and method of manufacturing the same)
As shown in
Next, on the insulating base 11 on which the electrode 12 is formed, an organic molecular crystal layer 13 including an aromatic compound is formed so as to bond to the side surface 12a of the electrode 12. As the aromatic compound included in the organic molecular crystal layer 13, those described above can be used and are selected as necessary. As a method of forming the organic molecular crystal layer 13, for example, a vacuum deposition method, a coating method, and an immersion method can be used and are selected as necessary. By forming the organic molecular crystal layer 13 so as to have a fine linear shape, it is possible to form a fine linear conductor.
In this case, by controlling the inclined angle θ of the side surface 12a of the electrode 12, it is possible to control the alignment of the organic molecular crystal layer 13 with respect to the electrode 12. For example, as shown in
The pattern shape and arrangement of the electrode 12 and organic molecular crystal layer 13 formed on the insulating base 11 are selected as necessary. In A to D of
According to the first embodiment, by controlling the inclined angle θ of the side surface 12a of the electrode 12, it is possible to control the alignment of the organic molecular crystal layer 13 in a portion bonded to the electrode 12 while substantially maintaining the layered structure of the organic molecular crystal layer 13. Therefore, it is possible to bond the organic molecular crystal layer 13 to the electrode 12 in the optimal alignment, to attempt to improve the characteristics of a grain boundary of the organic molecular crystal layer 13 in a portion bonded to the electrode 12, and to obtain favorable bonding characteristics, while utilizing the original characteristics of the organic molecular crystal layer 13. In particular, it is possible to smoothly move a carrier between the electrode 12 and the organic molecular crystal layer 13, and to attempt to reduce the transmission loss. Moreover, because the electrode 12 and organic molecular crystal layer 13 can be formed by a low temperature process or an ambient temperature process, by using a superconductor disclosed in Non-Patent Document 2 as the organic molecular crystal layer 13, it is possible to form a superconductor by a low temperature process or an ambient temperature process, which has been difficult previously, and to achieve an organic superconducting element. Furthermore, because the electrode 12 and organic molecular crystal layer 13 can be formed by a low temperature process or an ambient temperature process, by, for example, combining a molecular element or bio-element with a part of the electrode 12, it is possible to couple the superconductor with the molecular element or bio-element, or to integrate these elements.
As shown in
Next, on the insulating base 11 on which the electrode 12 is formed, the organic molecular crystal layer 13 is formed so as to bond to the upper side surface 12b and the lower side surface 12c of the electrode 12, similarly to the first embodiment. In this case, it is possible to align a portion of the organic molecular crystal layer 13, which is bonded to the upper side surface 12b, in parallel with the upper side surface 12b. Moreover, it is possible to align a portion of the organic molecular crystal layer 13, which is bonded to the lower side surface 12c, in a direction inclined with respect to the lower side surface 12c.
As shown in
Next, as shown in
Next, as shown in
A cross-sectional transmission electron micrograph of a sample in which the pentacene film 24 is formed in such a way is shown in
As described above, according to the second embodiment, the electrode 12 having the upper side surface 12b and the lower side surface 12c that have different inclined angles with respect to the main surface of the insulating base 11 is formed, and the organic molecular crystal layer 13 is formed so as to bond to the electrode 12. Therefore, it is possible to align a portion of the organic molecular crystal layer 13, which is bonded to the upper side surface 12b of the electrode 12, in parallel with the upper side surface 12b while substantially maintaining the layered structure of the organic molecular crystal layer 13, and to align a portion of the organic molecular crystal layer 13, which is bonded to the lower side surface 12c, in a direction inclined with the lower side surface 12c. Therefore, for example, it is possible to obtain favorable bonding characteristics at the bonding portion between the electrode 12 and the organic molecular crystal layer 13 while utilizing the original characteristics of the organic molecular crystal layer 13. The bonding structure is suitable for use in various organic elements, e.g., a transistor.
As shown in
In the third embodiment, other than the above are the same as those in the first embodiment.
According to the third embodiment, it is possible to obtain the same advantage as that of the first embodiment.
As shown in
In the fourth embodiment, other than the above are the same as those in the second embodiment.
According to the fourth embodiment, it is possible to obtain the same advantage as that of the first embodiment.
As shown in
On the organic molecular crystal layer 34, the source electrode 32, and the drain electrode 33, a gate insulating film 35 is formed. The gate insulating film 35 can be formed by for example, an insulating polymer. Examples of the polymer include polystyrene, polycarbonate, polydimethylsiloxane, nylon, polyimide, cyclic olefin copolymer, epoxy polymer, cellulose, polyoxymethylene, polyolefin polymer, polyvinyl polymer, polyester polymer, polyether polymer, polyamide polymer, fluorinated polymer, biodegradable plastic, phenol resin, amino resin, unsaturated polyester resin, diallyl phthalate resin, epoxy resin, polyimide resin, polyurethane resin, silicone resin, and copolymer obtained by combining various polymer units. Specific examples of the polymer include poly(α-methylstyrene) and cycloolefin copolymer. As the gate insulating film 35, an inorganic insulating film such as an SiO2 film may be used, as necessary. The thickness of the gate insulating film 35 is selected as necessary.
On the gate insulating film 35, a gate electrode 36 is provided. As the material of the gate electrode 36, various ones previously known can be used, and are selected as necessary.
[Method of Manufacturing Organic Transistor]
As shown in
Next, the organic molecular crystal layer 34 is formed, similarly to the first embodiment.
Next, an insulator is formed on the organic molecular crystal layer 34, the source electrode 32, and the drain electrode 33, by a vacuum deposition method, a coating method, an immersion method, or the like. Thus, the gate insulating film 35 is formed.
Next, after a film including a conductive material is formed on the gate insulating film 35 by a vacuum deposition method or the like, the film is patterned by an etching process. Thus, the gate electrode 36 is formed.
In this way, an intended top-gate organic transistor is manufactured.
According to the fifth embodiment, by controlling the inclined angles of the upper side surface 32a and lower side surface 32b of the source electrode 32, and the upper side surface 33a and lower side surface 33b of the drain electrode 33, it is possible to control the alignment of the organic molecular crystal layer 34 with respect to the source electrode 32 and the drain electrode 33. Therefore, it is possible to bond the organic molecular crystal layer 34 to the source electrode 32 and the drain electrode 33 in the optimal alignment, and to obtain favorable bonding characteristics. As a result, it is possible to cause the organic molecular crystal layer 34 to sufficiently show the original properties, and to obtain a top-gate organic transistor having favorable properties.
As shown in
The configuration of the organic transistor other than the above is the same as that of the organic transistor according to the fifth embodiment.
[Method of Manufacturing Organic Transistor]
As shown in
Next, the source electrode 32 and the drain electrode 33 are formed on the gate insulating film 35, similarly to the first embodiment.
Next, the organic molecular crystal layer 34 is formed, similarly to the first embodiment.
In this way, an intended bottom-gate organic transistor is manufactured.
According to the sixth embodiment, by the bottom-gate organic transistor, it is possible to obtain the same advantage as that of the fifth embodiment.
As shown in
[Method of Manufacturing Fine Linear Conductor]
As shown in
In the seventh embodiment, other than the above are the same as those in the first embodiment.
According to the seventh embodiment, it is possible to obtain the same advantage as that of the first embodiment in the case where the fiber-like insulator 41 is used as the insulating base. Moreover, it is possible to smoothly move a carrier between linear electrodes 42 and the linear organic molecular crystal layer 43 being an electrical lead, and to attempt to reduce the transmission loss. Furthermore, by using, for example, the superconductor disclosed in Non-Patent Document 2 as the linear organic molecular crystal layer 43, it is possible to achieve an organic superconducting element. According to the organic superconducting element, it is possible to attempt to improve the characteristics such as critical current of the organic molecular crystal layer 43 including a superconductor.
As shown in
[Method of Manufacturing Fine Linear Conductor]
As shown in
In the eighth embodiment, other than the above are the same as those in the first embodiment.
According to the eighth embodiment, it is possible to obtain the same advantage as that of the seventh embodiment.
As shown in
[Method of Manufacturing Fine Linear Conductor]
As shown in
In the ninth embodiment, other than the above are the same as those in the first embodiment.
According to the ninth embodiment, it is possible to obtain the same advantage as that of the seventh embodiment.
Although embodiments and Example have been specifically described, the present technology is not limited to the embodiments and Example, and various modifications can be made.
For example, the numerical value, structure, process, shape, material, and the like in the embodiments and Example are only examples, and different numerical value, structure, process, shape, material, and the like may be used as necessary.
Number | Date | Country | Kind |
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2011-075178 | Mar 2011 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2012/001555 | 3/7/2012 | WO | 00 | 9/18/2013 |