WO2013038537A1 - Electrode for photoelectric conversion devices, and photoelectric conversion device using same - Google Patents

Abstract

This electrode for photoelectric conversion devices is provided with a plurality of warp yarns (12A) and a plurality of weft yarns (12B), and the warp yarns and the weft yarns are woven so as to intersect each other one by one, thereby forming a net. The warp yarns are composed of a plurality of first metal wires (121), a plurality of second metal wires (122) and a plurality of first insulating wires (123). The first metal wires and the second metal wires are alternately arranged, and the first insulating wires are provided between the first metal wires and the second metal wires. The weft yarns are composed of second insulating wires. The first metal wires function as p-type electrodes, and the second metal wires function as n-type electrodes.

Description

Electrode for photoelectric conversion device and photoelectric conversion device using the same

The present invention relates to an electrode for a photoelectric conversion device used for a photoelectric conversion device and a photoelectric conversion device using the same.

A photoelectric conversion device is a device that converts light into electrical energy and a device that converts electrical energy into light. Examples of the former include solar cells, and examples of the latter include light emitting diodes.

Today, the need for solar power supply as a clean energy is recognized again. There are various types of solar cells such as Si solar cells, compound solar cells, and organic semiconductor thin film solar cells.

The Si solar cell will be described by taking a single crystal Si solar cell as an example. A p-type single crystal wafer is converted into a pn junction by changing the surface layer of the wafer to an n-type semiconductor by vapor phase diffusion or implantation of n-type impurity ions. A pin junction is created. Then, a solar cell having a sandwich structure is manufactured by forming the front electrode and the back electrode.

There are various types of compound solar cells, but they have the advantages of high energy conversion efficiency, low light degradation due to secular change, excellent radiation resistance, wide light absorption wavelength range, and large light absorption coefficient. A chalcopyrite solar cell will be described as an example. This is a solar cell provided with a CIGS layer made of a chalcopyrite compound (Cu (In + Ga) Se ₂ ) containing elements of Group I, Group III and Group VI as constituent components as a p-type light absorption layer (for example, Patent Documents). 1).

This solar cell with a CIGS layer generally prevents a back electrode layer, which is a positive electrode made of a Mo metal layer, on a glass substrate such as a soda lime glass (SLG) substrate, and Na unevenness caused by the SLG substrate. For forming a multilayer structure including a Na dip layer, a CIGS light absorption layer, an n-type buffer layer, and an outermost surface layer formed of a transparent electrode layer as a negative electrode.
Here, the n-type buffer layer is made of CdS, ZnO, InS or the like, and the transparent electrode layer is made of ZnOAl or the like.

In this multilayer laminated structure, when irradiation light enters from the light receiving portion on the surface, a pair of electrons and holes are generated in the vicinity of the pn junction of the multilayer laminated structure by being excited by the irradiation light having energy greater than the band gap. The excited electrons and holes reach the pn junction by diffusion, and the electrons are collected in the n region and the holes are separated in the p region due to the internal electric field of the junction. As a result, the n region is negatively charged, the p region is positively charged, and a potential difference is generated between the electrodes provided in each region. Using this potential difference as an electromotive force, a photocurrent is obtained when the electrodes are connected by a conductive wire.

The CIGS light absorbing layer is obtained by the following process. That is, the substrate itself provided with the In layer and the Cu—Ga layer as a precursor is accommodated in the annealing chamber and preheated. Thereafter, the precursor is converted into a CIGS layer by raising the temperature of the chamber to a temperature range of 500 to 520 ° C. while introducing H ₂ Se gas through a gas introducing tube inserted into the annealing chamber.

On the other hand, organic semiconductor thin film solar cells are attracting attention as solar cells suitable for mass production because they can be formed by a coating method. The organic solar cell has a so-called bulk heterojunction structure in which an organic donor material and an organic acceptor material are mixed. Among them, an organic thin-film solar cell capable of forming a cathode on a flexible substrate by coating and a low-temperature process has been developed (for example, Patent Document 2).

According to Patent Document 2, an organic semiconductor thin film solar cell has a structure in which an anode, a photoelectric conversion layer having a bulk heterojunction structure, and a cathode are sequentially laminated on one surface of a substrate, and a silver oxide and a reducing agent By forming a laminated structure in which an electron transport layer doped with an organic metal is applied in the vicinity of the cathode, not only the cathode is formed at a low temperature, but also the bonding between the organic metal doped layer and the cathode is improved. It is said.

Japanese Patent Laid-Open No. 2006-196771 JP 2011-124468 A

However, in the conventional structure, it was necessary to provide a pair of electrodes across a region that becomes a pn junction. For this reason, the light irradiation side electrode is required to have good light transmittance and low electrical resistance. For this reason, the light irradiation side electrode needs to be formed by vapor deposition or plating of an expensive rare metal. In addition, the process steps are complicated accordingly.
Further, the conventional solar cell has no flexibility, and when it is attached to the surface of a curved member, it needs to be subdivided.

Therefore, an object of the present invention is to provide an electrode structure for a photoelectric conversion device that does not require light transmittance as an electrode material and a photoelectric conversion device using the same.

In order to achieve the above object, an electrode for a photoelectric conversion device of the present invention is an electrode provided on one side of a photoelectric conversion layer that converts light and electrical energy, and includes a plurality of warp yarns and a plurality of weft yarns. The warp yarn and the weft yarn intersect each other to constitute a net, and the warp yarn comprises a plurality of first metal wires, a plurality of second metal wires, and a plurality of first insulating wires, The first metal wire and the second metal wire are alternately arranged, the first insulating wire is provided between the first metal wire and the second metal wire, and the weft is the second insulating wire. The first metal wire functions as a p-type electrode, and the second metal wire functions as an n-type electrode. A plurality of the first insulating wires may be provided between the first metal wire and the second metal wire.

In order to achieve the above object, in the photoelectric conversion device of the present invention, a p-layer organic semiconductor made of a hole transport material is provided on the first metal wire with respect to the electrode for an optoelectronic device, and An n-layer organic semiconductor made of an electron transport material is provided on the second metal wire, and the p-layer organic semiconductor and the n-layer organic semiconductor are alternately arranged, for example, alternately formed on the same surface. It is characterized by that. Here, the same surface may be either a virtual surface or a substrate surface, but when formed on the substrate surface, it may be a flat substrate or a flexible substrate that can be bent. The p-layer organic semiconductor and the n-layer organic semiconductor are covered with a transparent protective layer.

Conventionally, a p-layer organic semiconductor is laminated on one electrode and an n-layer organic semiconductor is laminated thereon to form a pn junction, and a transparent electrode is formed on the n-layer organic semiconductor as the other electrode. Although the photoelectric conversion device is configured by sequentially stacking, according to the present invention, one electrode functioning as a p-type electrode and the other electrode functioning as an n-type electrode are formed on the same surface. Therefore, the transparent electrode material conventionally required as the electrode material becomes unnecessary. This alternating array planar electrode structure can be fabricated on a flexible substrate such as a glass substrate. Since an organic semiconductor can be provided on the electrode by coating, the manufacturing process is not complicated, and the organic semiconductor can be manufactured at low cost.

It is sectional drawing of the photoelectric conversion device which concerns on embodiment of this invention. It is a perspective view which shows the electrode structure in the photoelectric conversion device shown in FIG. It is an enlarged view of the area | region of the code | symbol A shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In particular, the photoelectric conversion device will be described assuming that a solar cell converts light into electric energy. However, the present invention can also be applied to a device that converts electric energy into light energy.

FIG. 1 is a cross-sectional view of a photoelectric conversion device 1 according to an embodiment of the present invention, and FIG. 2 is a perspective view of the photoelectric device.

The photoelectric conversion device 1 includes an insulating substrate 11, an electrode 12 provided on the upper surface of the substrate 11, a photoelectric conversion layer 13 that covers the electrode 12, and a protective layer 14 that covers the upper surface of the photoelectric conversion layer 13. It is configured. In FIG. 2, the display of the photoelectric conversion layer 13 and the protective layer 14 is omitted.

The base material 11 is formed in a sheet shape and has flexibility. For example, what was formed as a flexible substrate by PET etc. is used. In this embodiment, as shown in FIG. 2, the base material 11 has a rectangular outline. Hereinafter, for convenience of explanation, the short side is referred to as the first side 11A, and the long side is referred to as the second side 11B.

The electrode 12 will be described with reference to FIG. The electrode 12 extends along the first side 11 </ b> A of the base material 11, and further has a plurality of warps 12 </ b> A arranged at a predetermined pitch in the extending direction of the second side 11 </ b> B, and the second side 11 </ b> B of the base material 11. And a plurality of weft yarns 12B arranged at a predetermined pitch in the extending direction of the first side 11A. The warp yarn 12A and the weft yarn 12B are woven so as to intersect each other. That is, the electrode 12 is formed in a plain weave net shape.

As the warp yarn 12A extending along the first side 11A, three types of wires are used. Specifically, the 1st metal wire 121, the 2nd metal wire 122, and the 1st insulated wire 123 are utilized.
As shown in FIG. 2, the first metal wire 121 and the second metal wire 122 are alternately arranged on the base material 11, and the first metal wire 121 and the second metal wire 122 are arranged between the first metal wire 121 and the second metal wire 122. One insulating wire 123 is provided. In addition, although the space | interval of the 1st metal wire 121 and the 2nd metal wire 122 is equivalent to the diameter of the cross section of the 1st insulation wire 123 pinched | interposed between them, in order to make an understanding of a structure easy in drawing. In the figure, a gap is provided between the members.

As the first metal wire 121 and the second metal wire 122, for example, a copper wire, a stainless wire, a wire obtained by performing metal plating on the surface of a chemical fiber, or the like can be used. One end 121E of each first metal wire 121 is connected to the first bus bar 121A as shown in FIG. Each second metal wire 122 has an end 122E located on the other end 121F side of the first metal wire 121 connected to the second bus bar 122A.

The first insulating wire 123 is made of a flexible insulating resin such as nylon resin, silicone resin, urethane resin, epoxy resin, polycarbonate resin, or vinyl resin.

The second insulating wire is used as the weft 12B extending along the second side 11B. Similar to the first insulating wire 123, the second insulating wire is made of a flexible insulating resin such as nylon resin, silicone resin, urethane resin, epoxy resin, polycarbonate resin, or vinyl resin.

The first metal wire 121, the second metal wire 122, the first insulating wire 123, and the second insulating wire are set to a thickness of about 20 μm to 30 μm.

Next, the photoelectric conversion layer 13 will be described.
FIG. 3 is a schematic enlarged view of a circle A region in FIG. The photoelectric conversion layer 13 is provided on one electrode, that is, the p-layer organic semiconductor 13A made of a hole transport material provided on the first metal wire 121 and the second metal wire 122 serving as the other electrode. And an n-layer organic semiconductor 13B made of a transport material. Therefore, one first metal wire 121 functions as a p-type electrode, and the other second metal wire 122 functions as an n-type electrode. The p-layer organic semiconductor 13A and the n-layer organic semiconductor 13B form a pn junction.

Next, materials of the p-layer organic semiconductor 13A and the n-layer organic semiconductor 13B will be described.
The p-layer organic semiconductor 13A is formed of a hole transport material. As a hole transport material, in addition to triphenylamine (TAPC) represented by the chemical formula (1), TPD and other aromatic amines which are dimers of triphenylamine represented by the chemical formula (2), the chemical formula (3) Α-NPD represented by formula (4), (DTP) DPPD represented by formula (4), m-MTDATA represented by formula (5), HTM1 represented by formula (6), 2-TNATA represented by formula (7), TPTE1 represented by the chemical formula (8), TCTA represented by the chemical formula (9), NTPA represented by the chemical formula (10), spiro TAD represented by the chemical formula (11), TFREL represented by the chemical formula (12), and the like are used.

The n-layer organic semiconductor 13B is formed of an electron transport material. Examples of the electron transport material include Alq ₃ represented by the chemical formula (13), BCP represented by the chemical formula (14), an oxadiazole derivative represented by the chemical formula (15), and an oxadiazole dimer represented by the chemical formula (16). And Starbust Oxadiazole represented by Chemical Formula (17), Triazole Derivative represented by Chemical Formula (18), Phenylxoxaline Derivative represented by Chemical Formula (19), Silole Derivative represented by Chemical Formula (20), and the like.

As described above, the first metal wire 121 and the second metal wire 122 that constitute the photoelectric conversion device electrode 12 are formed side by side on the base material 11, and the first metal wire 121 and the second metal wire 122 are further formed. The p-layer organic semiconductor 13 </ b> A and the n-layer organic semiconductor 13 </ b> B are formed side by side on the substrate 11, similarly to the first metal wire 121 and the second metal wire 122. Therefore, the surface on which light is incident can be used as the protective layer 14 without providing an electrode as in Patent Document 2.

The protective layer 14 is provided so as to cover the p-layer organic semiconductor 13A and the n-layer organic semiconductor 13B.
The protective layer 14 is formed of, for example, a resin or the like as long as it is a material that transmits irradiation light such as sunlight.

A method for producing the photoelectric conversion device 1 shown in FIG. First, the base material 11 is prepared. Next, a first metal wire 121, a second metal wire 122, a first insulating wire 123, and a second insulating wire are prepared and plain woven. The electrode 15 formed by plain weaving is fixed on the base material 11 with, for example, an adhesive. Thereafter, a hole transport material to be the p-layer organic semiconductor 13A is applied on a predetermined portion, for example, the first metal wire 121 as one electrode. For the application, for example, a printing method using an inkjet printer can be applied.

Next, an electron transport material to be an n-layer organic semiconductor 13B is applied between the p layer and the p layer, for example, on the second metal wire 122 as the other electrode. For the application, a printing technique using an ink jet printer can be used as in the case of the p-layer organic semiconductor 13A.

Thereby, a pn junction is formed by the p-layer organic semiconductor 13A and the n-layer organic semiconductor 13B. The n-layer organic semiconductor 13B may be applied, and then the p-layer organic semiconductor 13A may be applied.

Thereafter, the photoelectric conversion device 1 is manufactured by forming the protective layer 14 by painting or the like. Note that the method is not limited to the above-described method as long as the photoelectric conversion device 1 illustrated in FIG. 1 is manufactured.

Thus, according to this invention, the 1st metal wire 121 and the 2nd metal wire 122 which comprise the electrode 12 for photoelectric conversion devices are formed on the base material 11, Furthermore, the 1st metal wire 121 and the 2nd metal A p-layer organic semiconductor 13 </ b> A and an n-layer organic semiconductor 13 </ b> B are formed on the substrate 11 so as to cover the wire 122. Therefore, the surface on which light is incident can be used as the protective layer 14 without providing an electrode as in Patent Document 2. Therefore, it is not necessary to configure the electrode provided on the light irradiation side of Patent Document 2 with a transparent electrode, and it is not necessary to use a rare metal for the transparent electrode as a material. Therefore, Cu, Al, etc. can be used for the electrode 12 for photoelectric conversion devices.
Moreover, since the electrode 12 is comprised with the net | network which has flexibility, the photoelectric conversion device 1 can be attached to the curved surface after forming in planar shape.

Although the embodiments of the present invention have been described above, the present invention can be implemented with appropriate modifications within the scope of the present invention.
In the configuration described above, the configuration in which one first insulating wire 123 is provided between the first metal wire 121 and the second metal wire 122 has been described.
Further, the photoelectric conversion device may be configured by omitting the base material 11.

1: photoelectric conversion device 11: base material 12: electrode 12A for photoelectric conversion device: warp 12B: weft 121: first metal wire 122: second metal wire 123: first insulating wire 13A: p-layer organic semiconductor 13B: n-layer organic semiconductor 14: protective layer

Claims (4)

An electrode provided on one side of a photoelectric conversion layer that converts light and electrical energy,
A plurality of warp yarns and a plurality of weft yarns,
The warp yarn and the weft yarn intersect each other to form a net,
The warp is composed of a plurality of first metal wires, a plurality of second metal wires, and a plurality of first insulating wires,
The first metal wire and the second metal wire are alternately arranged, and the first insulating wire is provided between the first metal wire and the second metal wire,
The weft is made of a second insulating wire,
An electrode for a photoelectric conversion device, wherein the first metal wire functions as a p-type electrode and the second metal wire functions as an n-type electrode. 2. The photoelectric conversion device electrode according to claim 1, wherein a plurality of the first insulating wires are provided between the first metal wire and the second metal wire. 3. 3. The optoelectronic device electrode according to claim 1, wherein a p-layer organic semiconductor made of a hole transport material is provided on the first metal wire, and an electron transport is provided on the second metal wire. An n-layer organic semiconductor made of a material is provided, and the p-layer organic semiconductor and the n-layer organic semiconductor are alternately arranged. The photoelectric conversion device according to claim 3, wherein the organic semiconductor of the p layer and the organic semiconductor of the n layer are covered with a transparent protective layer.

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