Organic thin film photovoltaic device module and electronic apparatus

An organic thin film photovoltaic device module includes: a substrate; a first and second transparent electrode layers disposed on the substrate; an organic layer disposed on the substrate and the first and second transparent electrode layers; a plurality of dot-shaped contact holes formed so as to pass through up to the second transparent electrode layer in a perpendicular-to-plane direction with respect to the organic layer; a metal electrode layer disposed on the organic layer and on the second transparent electrode layer via the dot-shaped contact hole; and a passivation layer disposed on the metal electrode layer. There are provided: the organic thin film photovoltaic device module having satisfactory appearance without deteriorating appearance thereof and having the improved structure of the portion jointed in series; and the electronic apparatus.

FIELD

The embodiment described herein relates to an organic thin film photovoltaic device module and an electronic apparatus.

BACKGROUND

Since organic thin film photovoltaic devices characterized by ultra-thin structure, lightness in weight, and flexibility are fabricated using printing methods, e.g. an ink-jet process, under room temperature and atmospheric pressure, well-designed solar cells having a high flexibility of shape can be realized.

In ordinary organic thin film photovoltaic device modules, in order to realize a high open voltage, there have been adopted structures so that adjacent cells are connected to one another in series so as to be overlapped one another in a strip shape.

SUMMARY

The embodiment provides: The embodiment provides: an organic thin film photovoltaic device module having satisfactory appearance without deteriorating appearance thereof; and an electronic apparatus.

According to one aspect of the embodiment, there is provided an organic thin film photovoltaic device module comprising: a substrate; first and second transparent electrode layers disposed on the substrate; an organic layer disposed on the substrate and the first and second transparent electrode layers; a plurality of dot-shaped contact holes formed so as to pass through up to the second transparent electrode layer in a perpendicular-to-plane direction with respect to the organic layer; a metal electrode layer disposed on the organic layer and on the second transparent electrode layer via the dot-shaped contact hole; and a passivation layer disposed on the metal electrode layer.

According to another aspect of the embodiment, there is provided an organic thin film photovoltaic device module comprising an organic thin film photovoltaic device cell, the organic thin film photovoltaic device cell comprising: a substrate; first and second transparent electrode layers disposed on the substrate; an organic layer disposed on the substrate and the first and second transparent electrode layers; a plurality of dot-shaped contact holes formed so as to pass through up to the second transparent electrode layer in a perpendicular-to-plane direction with respect to the organic layer; a metal electrode layer disposed on the organic layer and on the second transparent electrode layer via the dot-shaped contact hole; and a passivation layer disposed on the metal electrode layer, wherein a plurality of the organic thin film photovoltaic device cells are connected to one another in series.

According to still another aspect of the embodiment, there is provided an electronic apparatus comprising the above-mentioned organic thin film photovoltaic device module.

According to the embodiment, there can be provided: the organic thin film photovoltaic device module having satisfactory appearance without deteriorating appearance thereof and having the improved structure of the portion jointed in series; and the electronic apparatus.

DESCRIPTION OF EMBODIMENTS

Next, the embodiment will be described with reference to drawings. In the description of the following drawings, the identical or similar reference numeral is attached to the identical or similar part. However, it should be noted that the drawings are schematic and therefore the relation between thickness and the plane size and the ratio of the thickness differs from an actual thing. Therefore, detailed thickness and size should be determined in consideration of the following explanation. Of course, the part from which the relation and ratio of a mutual size differ also in mutually drawings is included.

Moreover, the embodiment shown hereinafter exemplifies the apparatus and method for materializing the technical idea; and the embodiment does not specify the material, shape, structure, placement, etc. of each component part as the following. The embodiment may be changed without departing from the spirit or scope of claims.

In an organic thin film photovoltaic device module according to the following embodiment, “transparent” is defined as that whose transmissivity is not less than approximately 50%. In the organic thin film photovoltaic device module according to the embodiment, the “transparent” is used for the purpose of being transparent and colorless with respect to visible light. The visible light is equivalent to light having a wavelength of approximately 360 nm to approximately 830 nm and energy of approximately 3.45 eV to approximately 1.49 eV, and it can be said that it is transparent if the transmission rate is not less than 50% in such a region.

Comparative Example

FIG. 1shows a schematic planar pattern configuration at a side of a light-receiving surface of the organic thin film photovoltaic device module100A according to a comparative example, andFIG. 2shows a schematic planar pattern configuration at a side of a terminal-extracting surface thereof. Moreover,FIG. 3shows a schematic cross-sectional structure taken in the line I-I ofFIG. 2, andFIG. 4shows an example of an optical micrograph corresponding to the portion A shown inFIG. 1.

Moreover,FIG. 5shows a schematic enlarged view of the portion B shown inFIG. 1, andFIG. 6shows a schematic enlarged view of the portion C shown inFIG. 2.

As shown inFIGS. 1-3, the organic thin film photovoltaic device module100A according to the comparative example includes: a substrate10; a first transparent electrode layer111and a second transparent electrode layer112disposed on the substrate10; an organic layer14disposed on the substrate10and the transparent electrode layers111,112,113,114,115; a striped contact hole formed so as to pass through up to the transparent electrode layers112,113,114,115in a perpendicular-to-plane direction with respect to the organic layer14; a metal electrode layer disposed on the transparent electrode layers112,113,114,115and on the organic layer14via the striped contact hole; and passivation layers26,28,30,32disposed on the metal electrode layers161,162,163,164.

FIG. 7, shows an explanatory diagram of a size of each unit at a side of a terminal-extracting surface of the organic thin film photovoltaic device module according to the comparative example, andFIG. 8shows an explanatory diagram of a size of each unit at a side of a light-receiving surface.

InFIG. 7, the width W1of the organic thin film photovoltaic device module according the comparative example is approximately 10.3 mm, for example, the module length L1thereof is approximately 29.6 mm, for example, and the length LAof an anode extracting electrode A is approximately 3.8 mm, for example.

InFIG. 8, the cell width WEof the organic thin film photovoltaic device module according to the comparative example is approximately 8.6 mm, for example, and the cell length Lcthereof is approximately 6.75 mm, for example. Moreover, the length LEof the light-receiving effective region having a 4-cells serial structure is approximately 27.85 mm, for example, and the length LEtof the entire light-receiving effective region is approximately 28.2 mm, for example.

In the organic thin film photovoltaic device module100A according to the comparative example, since an organic power generation layer (organic photovoltaic layer) is exposed to an external atmosphere when the transparent electrode layer and the metal electrode layer are bonded to each other, the organic power generation layer arbitrarily is separately coated directly using a printing method, e.g. an ink-jet process; or the organic layer is scribed into a stripe shape using high-density oxygen plasma or semiconductor lasers (e.g., a wavelength thereof is approximately 532 nm), and mechanical scribers.

In the organic thin film photovoltaic device module100A, in order to realize a high open voltage, there have been adopted structures so that adjacent organic thin film photovoltaic device cells are connected to one another in series so as to be overlapped one another in a strip shape. However, at the portion D where the cells are bonded to each other, since the transparent electrode layer11and the metal electrode layer16are directly contacted with each other, a stripe line60of the metal electrode layer16exposed to the outer appearance as shown inFIGS. 4 to 6, and thereby the outer appearance is impaired.

Embodiment

FIG. 9shows a schematic planar pattern configuration at the a of a light-receiving surface of an organic thin film photovoltaic device module100according to the embodiment, andFIG. 10shows a schematic planar pattern configuration at a side of a terminal-extracting surface thereof. Moreover, a schematic enlarged view of E portion ofFIG. 9is expressed as shown in FIG.11, and a schematic enlarged view of F portion ofFIG. 10is expressed as shown inFIG. 12.

In the organic thin film photovoltaic device module100according to the embodiment, a joined portion between the transparent electrode layer11and the metal electrode layer16provided in order to connect in series the adjacent organic thin film photovoltaic device cells1is not provided in stripe shape, an influence on the outer appearance is controlled by arranging dot-shaped contact holes50at a fixed interval, as shown inFIGS. 11-12.

FIG. 13shows a schematic cross-sectional structure taken in the line II-II ofFIG. 10corresponding to a portion with dot-shaped contact holes, in the organic thin film photovoltaic device module100according to the embodiment.FIG. 14shows a schematic cross-sectional structure taken in the line III-III ofFIG. 10corresponding to a portion without dot-shaped contact holes50.

As shown inFIGS. 9-14, the organic thin film photovoltaic device module100according to the embodiment includes: a substrate10; transparent electrode layers111,112,113,114,115disposed on the substrate10; an organic layer14disposed on the substrate10and the transparent electrode layers111,112,113,114,115; a plurality of dot-shaped contact holes50formed so as to pass through up to the transparent electrode layers112,113,114,115in a perpendicular-to-plane direction with respect to the organic layer14; metal electrode layers161,162,163,164disposed on the organic layer14and on the transparent electrode layers112,113,114,115via the dot-shaped contact holes50; and passivation layers26,28,30,32disposed on the metal electrode layers161,162,163,164.

Moreover, as shown inFIGS. 9-14, in the organic thin film photovoltaic device module100according to the embodiment, a plurality of organic thin film photovoltaic device cells may be connected in series, the organic thin film photovoltaic device cell including: a substrate10; transparent electrode layers111,112disposed on the substrate10; an organic layer14disposed on the substrate10and the transparent electrode layer111,112; a plurality of dot-shaped contact holes50formed so as to pass through up to the transparent electrode layer112in a perpendicular-to-plane direction with respect to the organic layer14; a metal electrode layer161disposed on the organic layer14and on the transparent electrode layer112via the dot-shaped contact hole50; and passivation layers26,28,30,32disposed on the metal electrode layer161.

In the present embodiment, the dot-shaped contact hole50may have a shape of any one of a circular shape, rectangular shape or square shape.

The passivation layers26,28,30,32may include an SiN film or SiON film.

Moreover, a multi-laminated protection film may be formed by repeatedly laminating a plurality of the passivation layers26. For example, the passivation layers26,30are formed including an inorganic protection film, e.g. an SiN film or SiON film; and the passivation layers28,32may be formed including an organic protective film, e.g. a resin layer.

In the organic thin film photovoltaic device module100according to the embodiment, in order to realize a high open voltage, there have been adopted structures so that adjacent organic thin film photovoltaic device cells are connected to one another in series so as to be overlapped one another in a strip shape. In addition, an influence on the outer appearance can be controlled by arranging the dot-shaped contact holes50for a joined portion between the transparent electrode layer11and the metal electrode layer16provided in order to connect the adjacent organic thin film photovoltaic device cells1to each other in series, at a fixed interval or unfixed interval.

FIG. 15, shows an explanatory diagram of a size of each unit at a side of a terminal-extracting surface of the organic thin film photovoltaic device module according to the embodiment, andFIG. 16shows an explanatory diagram of a size of each unit at a side of a light-receiving surface.

InFIG. 15, the width W1of the organic thin film photovoltaic device module according the embodiment is approximately 10.3 mm, for example, the module length L1thereof is approximately 29.6 mm, for example, and the length LAof an anode extracting electrode A is approximately 3.8 mm, for example.

InFIG. 16, the cell width WEof the organic thin film photovoltaic device module according to the embodiment is approximately 8.6 mm, for example, and the cell length Lcthereof is approximately 6.75 mm, for example. Moreover, the length LEof the light-receiving effective region having a 4-cells serial structure is approximately 27.85 mm, for example, and the length LEtof the entire light-receiving effective region is approximately 28.2 mm, for example.

In the organic thin film photovoltaic device module100according to the embodiment,FIG. 17Ashows an arrangement example of circular dots as a shape of the dot-shaped contact holes50,FIG. 17Bshows an arrangement example of rectangular dots, andFIG. 17Cshows an arrangement example of square dots. In the present embodiment, the diameter D1of the circular dot is approximately 1 μm to approximately 100 μm, for example. The horizontal width D2of the rectangular dot is also approximately 1 μm to approximately 100 μm, for example. The horizontal width D3of the square dot is also approximately 1 μm to approximately 100 μm, for example.

Moreover, the interval of each dot is also approximately 10 μm to approximately 100 μm. The interval of each dot may be a fixed interval, or may be unfixed interval.

FIG. 18Ashows an arrangement example to which the circular-dot-shaped contact holes50are applied, as a schematic planar pattern configuration at the side of the light-receiving surface, in the organic thin film photovoltaic device module100according to the embodiment.FIG. 18Bshows a schematic planar pattern configuration at the side of the terminal-extracting surface thereof.

Similarly,FIG. 19Ashows an arrangement example to which the rectangular-dot-shaped contact holes50are applied, as a schematic planar pattern configuration at the side of the light-receiving surface, in the organic thin film photovoltaic device module100according to the embodiment.FIG. 19Bshows a schematic planar pattern configuration at the side of the terminal-extracting surface thereof.

Similarly,FIG. 20Ashows an arrangement example to which the squarer-dot-shaped contact holes50are applied, as a schematic planar pattern configuration at the side of the light-receiving surface, in the organic thin film photovoltaic device module100according to the embodiment.FIG. 20Bshows a schematic planar pattern configuration at the side of the terminal-extracting surface thereof.

In addition, the shape of the dot-shaped contact hole50is not limited to the above-mentioned examples, but it may be arranged in a line shape, e.g. a shape of a dashed line, a shape of a dashed dotted line, etc., although it is not a stripe. More specifically, the dot shape for patterning the organic layer may not be limited to the circular shape, but may be a linear shape, a rectangular parallelopiped shape, a rectangular shape, a square shape, etc. As a shape of a cubic shape, it may be a pillar shape or rectangular parallelopiped shape. The rectangular parallelopiped shape disclosed herein is a cubic shape in which each six cubic plane is a rectangular shape (at least one is always the rectangular shape) or square shape.

In the organic thin film photovoltaic device module100A according to the comparative example, since an organic power generation layer (organic photovoltaic layer) is exposed to an external atmosphere when the transparent electrode layer and the metal electrode layer are bonded to each other, the organic power generation layer arbitrarily is separately coated directly using a printing method, e.g. an ink-jet process; or the organic layer is scribed into a stripe shape using high-density oxygen plasma or semiconductor lasers (e.g., a wavelength thereof is approximately 532 nm), and mechanical scribers.

On the other hand, in the organic thin film photovoltaic device module100according to the embodiment, the junction between the adjacent cell is performed by providing the organic layer at an interval of approximately 10 μm or more (e.g., the circular dots of which the diameter is equal to or larger than approximately 1.0 μm are provided at a fixed or unfixed interval). By adopting such a configuration, the module excellent in a designedness of which the outer appearance of the joined portion is not impaired can be realized.

In the organic thin film photovoltaic device module100according to the embodiment, the organic layer14may includes a hole transport layer disposed on the transparent electrode layer11, and a bulk heterojunction organic active layer disposed on the hole transport layer.

Moreover, in the organic thin film photovoltaic device module100according to the embodiment, the multi-laminated protection film may includes a passivation layer26, a passivation layer (colored barrier layer)28, a back sheet passivation layer30, and a resin layer40. The colored barrier layer28disclosed herein can be formed of an ultraviolet (UV) curing resin, for example. Moreover, a coloring agent may be added to the colored barrier layer28. For example, carbon black etc. are applicable as a black coloring agent, phthalocyanine-based coating etc. are applicable as a blue coloring agent, and alizarin-based coating etc. are applicable as a red coloring agent. The colored barrier layer28can cover a spot formed in the passivation layer26, e.g., an SiN film or SiON film. The colored barrier layer28disposed on the passivation layer26has a role of a protective layer of the cell.

The colored barrier layer28can be formed of color filters enabling arbitrary patterning by irradiation with UV rays.

As shown inFIGS. 13 and 14, the organic thin film photovoltaic device module100according to the embodiment is made by laminating the organic layer14having a thickness of approximately several 100 nm used for a power generation layer (photovoltaic layer) on the glass substrate10with ITO, and by evaporating metal layers, e.g. an aluminum, as the second electrode layer16.

Since pure aluminum formed as the second electrode layer16is easily oxidized, a passive state film may be formed thereon in order to improve durability.

Since the organic layer14is disposed on the substrate10, the passive state film formed thereon can prevent the occurrence of damage to the organic layers14when forming the passivation layer26.

According to the embodiment, there can be provided the organic thin film photovoltaic device module having satisfactory appearance without deteriorating appearance thereof and having the improved structure of the portion jointed in series.

FIG. 21shows a schematic diagram for explaining an operational principle of the organic thin film photovoltaic device cell1applicable to the organic thin film photovoltaic device module according to the embodiment. Moreover, an energy band structure of various kinds of materials used for the organic thin film photovoltaic device cell1shown inFIG. 21is expressed as shown inFIG. 22. With reference toFIGS. 21 and 22, there will now be explained theoretic configuration and operation of the organic thin film photovoltaic device cell1according to the embodiment.

As shown in the left-hand side ofFIG. 21, the organic thin film photovoltaic device cell1according to the embodiment includes: a substrate10; an optically transmissive electrode layer11disposed on the substrate10; a hole transport layer12disposed on the optically transmissive electrode layer11; a bulk heterojunction organic active layer14A disposed on the hole transport layer12; and a second electrode layer16disposed on the bulk heterojunction organic active layer14A. The second electrode layer16is formed of aluminum (Al), for example, and used for cathode electrode layer.

In this case, the bulk heterojunction organic active layer14A forms a complicated bulk hetero pn junction such that p type organic active layer regions and n type organic active layer regions are existed, as shown in the right-hand side ofFIG. 21. In the embodiment, the p type organic active layer region is formed of P3HT (poly (3-hexylthiophene-2, 5diyl)), for example, and the n type organic active layer region is formed of PCBM (6,6-phenyl-C61-butyric acid methyl ester), for example.

(a) Firstly, when light is absorbed, photon generation of excitons occur in the bulk heterojunction organic active layer14A.

(b) Next, the excitons are dissociated to free carriers of electrons (e−) and holes (h+) by spontaneous polarization, in the pn junction interfaces in the bulk heterojunction organic active layer14A.

(c) Next, the dissociated holes (h+) travel towards the optically transmissive electrode layer11acting as an anode electrode, and the dissociated electrons (e−) travel towards the cathode electrode layer16.

(d) As a result, between the cathode electrode layer16and the optically transmissive electrode layer11, a reverse current conducts and an open circuit voltage Voc occurs, and thereby the organic thin film photovoltaic device cell1can be obtained.

In the organic thin film photovoltaic device cell1, a chemical structural formula of PEDOT is expressed as shown inFIG. 23A, and a chemical structural formula of PSS is expressed as shown inFIG. 23B, among PEDOT: PSS applied to the hole transport layer12.

In the organic thin film photovoltaic device cell1according to the embodiment, a chemical structural formula of P3HT applied to the bulk heterojunction organic active layer14A is expressed as shown inFIG. 24A, and a chemical structural formula of PCBM applied to the bulk heterojunction organic active layer14A is expressed as shown inFIG. 24B.

Although illustration is omitted, the passive state film is composed including an oxide film of the metal electrode layer16. Moreover, the oxide film of the metal electrode layer16can be formed with oxygen plasma treatment applied on the surface of the metal electrode layer16. The thickness of the passive state film is from approximately 10 angstroms to approximately 100 angstroms, for example. A passivation film disposed on the passive state film may be provided. The passivation film can be composed of an SiN film or an SiON film, for example.

The metal electrode layer16may be composed including any one of metals, such as Al, W, Mo, Mn, or Mg. If the metal electrode layer16is formed including Al, the passive state film is an alumina (Al2O3) film.

Even in the case where moisture or oxygen is infiltrated into the organic layer14, the organic thin film photovoltaic device cell1including the passive state film on the surface of the metal electrode layer16can prevent a situation where the metal electrode layer16is oxidized due to the moisture or oxygen. Accordingly, degradation of the organic thin film photovoltaic device cell can be reduced, thereby improving the durability thereof.

The organic thin film photovoltaic device100according to the embodiment is formed by laminating approximately several 100-nm organic layer14used for a power generation layer (photovoltaic layer) on the glass substrate10with ITO, and then evaporating a metal, e.g. aluminum. Since a pure aluminum formed as the metal electrode layer16is easily oxidized, a multi-laminated protection film formed by laminating an inorganic passivation film and a resin protective film, e.g. SiN, SiON, as a multilayer with Chemical Vapor Deposition (CVD) method is used for a barrier layer in order to give a durability.

A fabrication method of the organic thin film photovoltaic device module100according to the embodiment includes: forming transparent electrode layers111,112,113,114,115on a substrate10; forming an organic layer14on the substrate10and the transparent electrode layers111,112,113,114,115; forming a plurality of dot-shaped contact holes50so as to pass through up to the transparent electrode layers112,113,114,115in a perpendicular-to-plane direction with respect to the organic layer14; forming metal electrode layers161,162,163,164on the organic layer14and on transparent electrode layers112,113,114,115via the dot-shaped contact holes50; and forming passivation layers26,28,30,32on the metal electrode layers161,162,163,164.

The process of forming passivation layers26,28,30,32may include forming a multi-laminated protection film.

The process of forming the dot-shaped contact holes50may include a patterning process by oxygen plasma.

The process of forming the organic layer14may includes a formation process by an ink-jet process.

The process of forming the dot-shaped contact holes50may include a process of separately coating and forming the organic layer14with the ink-jet process.

There will now be explained the fabrication method of a plurality (three pieces, as an example in Figures) of the organic thin film photovoltaic device modules arranged in series according to the embodiment.

FIG. 25Ashows a schematic plane configuration of a state where the transparent electrode layer11is pattern-formed on the substrate10, in a process of the fabrication method of the organic thin film photovoltaic device module100according to the embodiment, andFIG. 25Bshows a schematic cross-sectional structure taken in the line IV-IV ofFIG. 25A.

FIG. 26Ashows a schematic plane configuration of a state where the organic layer14is pattern-formed on the transparent electrode layer11, in a process of the fabrication method of the organic thin film photovoltaic device module100according to the embodiment, andFIG. 26Bshows a schematic cross-sectional structure taken in the line V-V ofFIG. 26A.

FIG. 27Ashows a schematic plane configuration of a state where the dot-shaped contact holes50which reach to the transparent electrode layer11is pattern-formed in the organic layer14, in a process of the fabrication method of the organic thin film photovoltaic device module100according to the embodiment, andFIG. 27Bshows a schematic cross-sectional structure taken in the line VI-VI ofFIG. 27A.

FIG. 28Ashows a schematic plane configuration of a state where the metal electrode layer16is pattern-formed on the organic layer14and on the transparent electrode layer11in the dot-shaped contact hole50, in a process of the fabrication method of the organic thin film photovoltaic device module100according to the embodiment.FIG. 28Bshows a schematic cross-sectional structure taken in the line VII-VII ofFIG. 28A.FIG. 28Bexpresses a schematic cross-sectional structure at a portion without the dot-shaped contact hole50.

Similarly,FIG. 29Ashows a schematic plane configuration of a state where the metal electrode layer16is pattern-formed on the organic layer14and on the transparent electrode layer in the dot-shaped contact hole50, in a process of the fabrication method of the organic thin film photovoltaic device module100according to the embodiment.FIG. 29Bshows a schematic cross-sectional structure taken in the line VIII-VIII ofFIG. 29A.FIG. 28Bexpresses a schematic cross-sectional structure at a portion with the dot-shaped contact holes50.

FIG. 30Ashows a schematic plane configuration of a state where the passivation layers26,25,30,32are formed on the metal electrode layer16, in a process of the fabrication method of the organic thin film photovoltaic device module100according to the embodiment.FIG. 30Bshows a schematic cross-sectional structure taken in the IX-IX ofFIG. 30A.

With reference toFIGS. 25-30, there will now be explained the fabrication method of the organic thin film photovoltaic device according to the embodiment, in which a plurality (three pieces, as an example in the figures) of the organic thin film photovoltaic device cells is arranged in series.

(a) Firstly, a glass substrate (of which the size is, for example, 50 mm in length×50 mm in width×0.7 mm in thickness) washed by pure water, acetone and ethanol is inserted into an Inductively Coupled Plasma (ICP) etcher, and adherents on the surface of the glass substrate are removed by O2plasma (Glass Substrate Surface Treatment). In order to efficiently guide the light to the organic layer, an antireflection process may be performed to the glass surface of the substrate10formed of a glass substrate. An alkali-free glass substrate with ITO may be used as the glass substrate, for example.
(b) Next, as shown inFIGS. 25A and 25B, the optically transmissive electrode layer11composed of, for example, ITO is pattern-formed on the glass substrate10. Specifically, the TCO is patterned by wet etching, such as aqua regia etching, using a positive resist, for example. The patterning of the transparent electrode layer11requires five processes, e.g., approximately 120 minutes. As a consequence, a plurality of the transparent electrode layers11are formed in a stripe pattern so as to sandwich a trench region.
(c) Next, as shown inFIGS. 26A and 26B, the organic layer14(the hole transport layer12and the bulk heterojunction organic active layer14A) is formed on each transparent electrode layer11. The process of applying and forming of the organic layer14requires two processes, e.g., approximately 60 minutes. The process of applying and forming of the organic layer14includes a film formation by a spin coat method, and a patterning process by high-density plasma etching, for example.
(c-1) Spin coating technology, spray technology, screen printing technology, etc. can be applied to the formation of the hole transport layer12. In this case, in the process for forming the hole transport layer12, the film formation is performed, for example, by spin coating of PEDOT:PSS, and annealing is applied thereto for approximately 10 minutes at 120 degrees Celsius (C) for the purpose of water removal. Oxygen plasma etching technology, laser patterning technology, etc. can be applied to the formation of the trench region.
(c-2) Next, the bulk heterojunction organic active layer14A is formed on each hole transport layer12. In the formation process of the bulk heterojunction organic active layer14A, film formation is performed with spin coating of P3HT and PCBM, for example.
(d) Next, as shown inFIGS. 27A27B, a plurality of the dot-shaped contact holes50are formed so as to pass through up to the transparent electrode layer11in a perpendicular-to-plane direction with respect to the organic layer14. An etching technology by high-density (oxygen) plasma is used for forming of the dot-shaped contact hole50with respect to the organic layer14(12,14A) required in order to be contacted with the transparent electrode layer11(TCO), for example. Moreover, laser light having approximately 5 μm in diameter (of which the wavelength is 532 nm, for example) may be used therefor. Consequently, the dot-shaped contact hole50is formed in the joined portion for connecting the adjacent organic thin film photovoltaic device cells to each other in series.
(e) Next, as shown inFIGS. 28A, 28B, andFIGS. 29A and 29B, the second electrode layer (cathode electrode layer)16is pattern-formed on the organic layer14and on the transparent electrode layer11via the dot-shaped contact hole50. The cathode electrode layer16is formed by depositing a metal layer (e.g., Al, W, Mo, Mn, Mg) by vacuum thermal vapor deposition, for example. Screen printing technology instead of the vacuum thermal vapor deposition may be applied to the formation of the cathode electrode layer16. The formation process of the cathode electrode layer16requires one process, e.g., approximately 2 minutes.
(f) Next, although illustration is omitted, after performing an etching process of the unnecessary organic layer14, an oxide film (passive state film) may be formed on a surface of the cathode electrode layer16. The passive state film can be formed by applying oxygen plasma treatment to the second electrode layer16. The passive state film can be formed using a high-density plasma etching apparatus, for example. It is also possible to perform an etching process of the organic layer14at the same time when the passive state film is formed by performing the oxygen plasma treatment of the second electrode layer16.
(g) Next, as shown inFIGS. 30A and 30B, the passivation layer26is formed on the entire surface of the device. In this case, the passivation layer26may be formed of a silicon nitride film etc. with the CVD. The thickness of the silicon nitride film is approximately 0.5 μm to approximately 1.5 μm, for example. Durability can be further improved by sealing with the SiN film formed by using CVD to reduce degradation due to moisture or oxygen in atmospheric air.
(h) Next, as shown inFIGS. 30A and 30B, the colored barrier layer28is formed on the passivation layer26. In order to eliminate defects, e.g. a spot etc. of the passivation layer26formed with the SiN film, and to smooth the back surface of the module, the UV curing resin material is coated with a spin coat method etc., then is cured by the UV irradiation. Coloring arbitrary to the module is enabled in the thin-layered element structure by using the protection film to which a coloring agent is added for the colored barrier layer28.
(i) Next, as shown inFIGS. 30A and 30B, the back sheet passivation layer30is formed on the colored barrier layer28. The back sheet passivation layer30may be formed of a silicon nitride film etc. with the CVD. The thickness of the silicon nitride film is approximately 0.5 μm to approximately 1.5 μm, for example. Durability can be further improved by sealing with the SiN film formed by using CVD to reduce degradation due to moisture or oxygen in atmospheric air. The cell sealing with the multi-layered protection film requires four processes, e.g., approximately 120 minutes.
(j) Next, although illustration is omitted, a bonding junction between an anode A electrode and a cathode K electrode of the organic thin film photovoltaic device module connected in series is formed. Carbon paste, Ag paste, etc. are used for the bonding junction, for example. The terminal electrode can be formed including a gold wire etc., for example.
(k) Finally, as shown inFIGS. 30A and 30B, it is protected with a UV curing resin from an intrusion of moisture, oxygen, etc.

According to the above-mentioned processes, the plurality (three pieces in the example in the figures) of the organic thin film photovoltaic device modules100according to the embodiment arranged in series can be completed.

(Fabrication Method of ITO Substrate)

FIG. 31Ashows an application and sintering process of a positive resist layer13, in the fabrication method of an ITO substrate in which the transparent electrode layer11is pattern-formed on the substrate10, in the fabrication method of the organic thin film photovoltaic device module100according to the embodiment. Moreover,FIG. 31Bshows an exposure process of the positive resist layer13,FIG. 31Cshows a developing process of a positive resist layer13,FIG. 31Dshows an aqua regia etching process of the transparent electrode layer11, andFIG. 31Eshows resist removing and substrate washing process of the positive resist layer13.

(a) Firstly, as shown inFIG. 31A, the positive resist layer13is coated on an ITO substrate, and then is sintered.

(b) Next, as shown inFIG. 31B, a positive mask17is pattern-formed on the positive resist layer13, and then is subjected to UV exposure.

(c) Next, as shown inFIG. 31C, the positive resist layer13is subjected to a development processing.

(e) Next, as shown inFIG. 31E, the positive resist layer13is removed, and then the substrate is subjected to a washing process. Consequently, the ITO substrate in which the transparent electrode layer11is pattern-formed on the glass substrate10is completed. The thickness of the transparent electrode layer11is approximately 0.15 μm, for example.

FIG. 32Ashows an example of an SEM observation of an aspect of an etching cross section of the patterning region SP in the transparent electrode layer11, inFIG. 31E, andFIG. 32Bshows an example of a cross-sectional profile thereof. As shown inFIG. 32A, the width of the patterning region SP is approximately 40 μm, and the depth thereof is approximately 140 nm.

FIG. 32Ais a schematic showing a spin coat method at the time of forming the hole transport layer12and the bulk heterojunction organic active layer14A, in the fabrication method of the organic thin film photovoltaic device module100according to the embodiment.FIG. 32Bshows a schematic bird's-eye view configuration of an example of the formed hole transport layer12and the formed bulk heterojunction organic active layer14A.

For example, if a relative small-area element is created, a spin coat method as shown inFIG. 32Acan be applied, in the organic thin film photovoltaic device module100according to the embodiment.

More specifically, a spin coater including a high-speed rotating spindle62connected to driving sources, e.g. a motor, and a table fixed to the spindle62, wherein the substrate10is mounted on the table63is used therefor, as shown inFIG. 32A.

Then, the driving source, e.g. a motor, is worked after the substrate10is mounted on the table63, and then the table63is rotated at a high speed, e.g., 2000-4000 rpm, in arrows A, B direction. Subsequently, a droplet64of a solution for forming the hole transport layer12and the bulk heterojunction organic active layer14A is dropped thereon using a syringe65. Thereby, the hole transport layer12and the bulk heterojunction organic active layer14A having uniform thickness (refer toFIG. 32B) can be formed with the droplet64on the substrate10in accordance with centrifugal force.

(Fabrication Method of Dot-Shaped Contact Hole)

FIGS. 34A to 34Cshow a fabrication method of the dot-shaped contact hole, in the fabrication method of the organic thin film photovoltaic device module100according to the embodiment. More specifically,FIG. 34Ashows a process of forming the organic layer14on the transparent electrode layer11with a spin coat method;FIG. 34Bshows a process of patterning the organic layer14and the transparent electrode layer11with high-density (oxygen) plasma21, after pattern formation of a metal mask19to be used for forming the dot-shaped contact hole; andFIG. 34Cshows a removing process of the metal mask19.

(A) Firstly, as shown inFIG. 33A, a process of applying and forming of the organic layer14is performed on the ITO substrate with a spin coat method. The process of applying and forming thereof requires approximately 80 seconds.

(b) Next, as shown inFIG. 33B, the organic layer14and the transparent electrode layer11are patterned thereon with the high-density (oxygen) plasma21after the metal mask19for forming the dot-shaped contact hole is patterned-formed on the organic layer14. The patterning process with the oxygen plasma requires approximately 50 minutes.
(c) Next, as shown inFIG. 33C, the metal mask is removed therefrom. As a consequence, the dot-shaped contact hole50is formed in the organic layer14and the transparent electrode layer11.
(Ink-Jet Process)

The dot-shaped contact hole50can also be formed with an ink-jet process, in the fabrication method of an organic thin film photovoltaic device module100according to the embodiment. More specifically, in the fabrication method of an organic thin film photovoltaic device module100according to the embodiment,FIG. 35Ashows an aspect that the organic material ink141is applied onto the ITO substrate from an ink head23with an ink-jet process.

Moreover,FIG. 35Bshows a process of forming the dot-shaped contact hole50by separately coating and forming the organic layer14with the ink-jet process on the ITO substrate.

(Producing Steps of Organic Thin Film Photovoltaic Device)

In accordance with the flow chart shown inFIG. 36, there will now be explained producing steps of the organic thin film photovoltaic device module100according to the embodiment.

(a) In Step S1, PEDOT:PSS is coated on the ITO substrate10. For example, PEDOT:PSS aqueous solution is filtered with a 0.45-μm PTFE membrane filter to remove undissolved matters and impurities, and then the PEDOT:PSS aqueous solution is coated on the ITO substrate10with spin coating (for example, 4000 rpm for 30 sec).
(b) In Step S2, the PEDOT:PSS is sintered. More specifically, heat-treatment is performed at 120 degrees C. for 10 minutes for the purpose of water removal, after the film formation. In addition, it is effective to cover a petri dish previously heated by a hot plate so that the heat may be transferred to whole of the substrate10. The hole transport layer12is formed on the transparent electrode layer11on the ITO substrate10by the above-mentioned processes.
(c) In Step S3, P3HT:PCBM is coated on the substrate10. Specifically, P3HT 16 mg and PCBM 16 mg are dissolved in dichlorobenzene (o-dichlorobenzene), for example. The solution is subjected to ultrasonic treatment for 1 minute at 50 degrees C., after agitating at 50 degrees C. under nitrogen atmosphere for a night. Spin coating of the solution is performed on the ITO substrate10subjected to washing treatment in a glove box replaced with nitrogen (<1 ppm O2, H2O). A rotational frequency of the spin coating is 2000 rpm per 1 sec after 550 rpm per 60 sec.
(d) In Step S4, pre-annealing is performed. More specifically, heating processing is performed for 10 minutes at 120 degrees C. after the coating of Step S3. In addition, it is effective to cover a petri dish previously heated by a hot plate so that the heat may be transferred to whole of the substrate10. By the above-mentioned processes, the bulk heterojunction organic active layer14A is formed on the hole transport layer12, and thereby the organic layer14(12+14A) is formed.
(e) In Step S5, LiF vacuum evaporation is performed. Specifically, as for LiF (purity: 99.98%), vacuum thermal evaporation is performed with the vacuum degree: 1.1×10−6torr and the vacuum evaporation rate: 0.1 angstrom/sec. The LiF used for an electronic injection layer with respect to the bulk heterojunction organic active layer14A.
(f) In Step S6, the dot-shaped contact hole50is formed so as to pass through the organic layer14and reach up to the transparent electrode layer11.
(g) In Step S7, Al vacuum evaporation is performed, and thereby the second electrode layer16is formed on the transparent electrode layer11and on the organic layer14in the dot-shaped contact hole50. Specifically, as for Al (purity: 99.999%), vacuum thermal evaporation is performed with the vacuum degree: 1.1×10−6torr and the vacuum evaporation rate: more than 2 angstroms/sec.
(h) In Step S8, an oxide film is formed on the second electrode layer16. Specifically, the surface of the second electrode layer16is oxidized with oxygen plasma by using a high-density plasma etching apparatus, thereby forming the oxide film (passive state film).
(i) In Step S9, passivation sealing is performed. Specifically, the passivation layer26, the colored barrier layer28, and the back sheet passivation layer30are formed to be laminated one after another on the whole device, and thereby passivation processing is performed.
(j) In Step S10, the terminal electrode is formed. Carbon paste, Ag paste, etc. are used for the bonding junction of the terminal electrode, for example.
(k) In Step S11, sealing is performed. Specifically, a peripheral portion thereof is protected by a resin layer32, e.g. a UV curing resin, etc. from infiltration of moisture, oxygen, etc.
(Electronic Apparatus)

The embodiment provides the organic thin film photovoltaic device having satisfactory appearance without deteriorating appearance thereof and having the improved structure of the portion jointed in series. Accordingly, it becomes easy to mount mobile terminal equipment etc. in the electronic apparatus. It is more effective for first extraction terminal electrodes not to be conspicuous at the time of mounting the cell of the organic thin film photovoltaic device on a bezel (peripheral part of the display) and the back surface of the display panel since an external view is important for electronic devices represented by in particular smart phones, tablet-type devices, etc. The plurality of the dot-shaped contact holes with respect to the organic layer14(12,14A) required in order to be contacted with the transparent electrode layer11(TCO) can be formed using high density (oxygen) plasma etching technology, or laser light having approximately 5 μm in diameter (of which the wavelength is 532 nm, for example). Since such a method is used, contact resistance can be reduced without impairing external appearance, and thereby forming satisfactory bonding.

As mentioned above, according to the embodiment, there can be provided: the organic thin film photovoltaic device module having satisfactory appearance without deteriorating appearance thereof and having the improved structure of the portion jointed in series; the fabrication method such an organic thin film photovoltaic device module; and the electronic apparatus.

Other Embodiments

As explained above, the embodiment has been described, as a disclosure including associated description and drawings to be construed as illustrative, not restrictive. This disclosure makes clear a variety of alternative embodiment, working examples, and operational techniques for those skilled in the art.

Such being the case, the embodiment described herein covers a variety of embodiments, whether described or not.

INDUSTRIAL APPLICABILITY

The organic thin film photovoltaic device module of the embodiment can be applied to wide fields, e.g. photovoltaic power generation panels, chargers for mobile terminals, etc.