This application makes reference to, incorporates into this specification the entire contents of, and claims all benefits accruing under 35 U.S.C. §119 from an application earlier filed in the Korean Intellectual Property Office on Mar. 10, 2010, and there duly assigned Serial No. 10-2010-0021377.
1. Field of the Invention
One or more embodiments of the present invention relate to a photoelectric conversion device and a manufacturing method thereof.
2. Description of the Related Art
Recently, diverse studies have been conducted regarding a photoelectric conversion device that converts light energy into electric energy. The photoelectric conversion device may be applied as one of resources to replace fossil fuels. In particular, a solar cell using solar energy has drawn wide attraction.
While studies on the solar cell having a variety of driving principles are being conducted, wafer-type silicon or crystal solar cells using the p-n conjunction of a semiconductor are most popular. The wafer-type silicon or crystal solar cells have a drawback, however, in that the manufacturing costs are high due to the process characteristic of forming and handling a highly pure semiconductor material.
It is therefore an aspect of the present invention to provide an improved photoelectric conversion device and a method for manufacturing thereof.
It is another aspect of the present invention to provide a photoelectric conversion device having improved sealing performance at an electrolyte injection hole and a simplified sealing process, and a manufacturing method thereof.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.
According to one or more embodiments of the present invention, a photoelectric conversion device includes first and second substrates, on which first and second electrodes are respectively formed, arranged to face each other, an electrolyte injected into a gap between the first and second substrates through an electrolyte injection hole formed in the first substrate, and an injection hole sealing member for sealing the electrolyte injection hole. The injection hole sealing member may include a cover portion for covering an entrance end of the electrolyte injection hole and an insertion portion extending from the cover portion along the electrolyte injection hole.
The cover portion may have a size larger than that of the entrance end of the electrolyte injection hole, and may cover the electrolyte injection hole.
The cover portion may be supported on the first substrate in a vicinity of the electrolyte injection hole.
A first sealing member may be disposed between the cover portion and the first substrate.
The insertion portion may be inserted in the electrolyte injection hole.
A second sealing member may be disposed between the insertion portion and an inner wall of the electrolyte injection hole.
The second sealing member may extend toward the gap between the first and second substrate.
The cover portion and the insertion portion may be integrally formed.
The injection hole sealing member may be formed of a heat conductive material.
The injection hole sealing member may include a metal material or a ceramic material.
The length of the insertion portion may be shorter than a sum of a thickness of the first substrate and a thickness of the gap between the first and second substrates.
The photoelectric conversion device may further include a first sealing member disposed between the cover portion and the first substrate, and a second sealing member disposed between the insertion portion and an inner wall of the electrolyte injection hole. The first and second sealing members may be formed of the same material.
The first and second sealing members may be continuously and integrally formed.
According to one or more embodiments of the present invention, a method of manufacturing a photoelectric conversion device includes preparing first and second substrates on which first and second electrodes are respectively formed, injecting an electrolyte into a gap between the first and second substrates through an electrolyte injection hole formed in the first substrate, preparing an injection hole sealing member for sealing the electrolyte injection hole, the injection hole sealing member comprising a cover portion for covering an entrance end of the electrolyte injection hole and an insertion portion extending from the cover portion along the electrolyte injection hole, adhering an auxiliary sealing member to at least a part of the injection hole sealing member, and sealing the electrolyte injection hole by using the injection hole sealing member.
The sealing operation includes a first operation of seating the injection hole sealing member in the electrolyte injection hole, and a second operation of pressing the injection hole to sealing member to insert the insertion portion into the electrolyte injection hole. The insertion portion may be disposed closer, than the cover portion, to the gap between the first and second substrates.
In the second operation, the injection hole sealing member may be pressed until the cover portion is supported on the first substrate around the electrolyte injection hole.
In the second operation, the injection hole sealing member may be pressed against the electrolyte injection hole and the auxiliary sealing member adhering to the injection hole sealing member may be simultaneously heated.
In the second operation, the injection hole sealing member may be pressed by using a press having a heating unit.
In the preparing of the injection hole sealing member, the injection hole sealing member may be formed of a heat conductive material.
A more complete appreciation of the invention, and many of the attendant advantages thereof, will be readily apparent as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference symbols indicate the same or similar components, wherein:
Unlike a silicon solar cell, a dye-sensitized solar cell mainly includes a photosensitive dye for receiving light having a wavelength of a visible light ray and generating excited electrons, a semiconductor material for accepting the excited electrons, and an electrolyte for reacting with electrons returning after passing through an external circuit. The dye-sensitized solar cell has a high photoelectric conversion efficiency compared to a contemporary solar cell. Thus, the dye-sensitized solar cell is expected as a next generation solar cell.
Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description.
Functional layers 118 and 128 are respectively formed on light receiving surface substrate 110 and opposite substrate 120, and include a semiconductor layer for generating excited electrons from incident light and electrodes to collect the generated electrons and to draw the collected electrons to an external circuit. For example, ends of the electrodes constituting functional layers 118 and 128 may extend to the outside of substrate sealing member 130 for connection to an external circuit (not shown).
Light receiving surface substrate 110 and opposite substrate 120 are combined and sealed together with a predetermined gap by interposing substrate sealing member 130 therebetween. Electrolyte 150 fills the sealed space between light receiving surface substrate 110 and opposite substrate 120. Substrate sealing member 130 is formed to surround electrolyte 150, thereby preventing electrolyte 150 from leaking to the outside by forming the sealed space.
Light electrode 114 and opposite electrode 124 are connected by a lead wire 190 and electrically connected to each other via an external circuit 180. In a modular structure in which a plurality of photoelectric conversion devices are connected in series/parallel, however, electrodes 114 and 124 of photoelectric conversion device 100 may be connected in series/parallel and both ends of a connection portion of electrodes 114 and 124 may be connected to external circuit 180.
Light receiving surface substrate 110 may be formed of a transparent material or a material having a high light transmissivity. For example, light receiving surface substrate 110 may be formed of a glass substrate or a resin film. The resin film exhibiting flexibility is suitable for a display device requiring flexibility
Light electrode 114 may include a transparent conductive film 111 and a grid electrode 113 having a mesh pattern formed on transparent conductive film 111. Transparent conductive film 111 is formed of a material having both of transparency and electric conductivity, for example, transparent conducting oxide (TCO) such as indium tin oxide (ITO), fluorine-doped tin oxide (FTO), or antimony-doped tin oxide (ATO). Grid electrode 113 is introduced to reduce the electric resistance of light electrode 114 and functions as a charge collection wire to collect electrons generated according to photoelectric conversion and provide a low-resistance current path. For example, grid electrode 113 may be formed on transparent conductive film 111, and may be formed of a metal material such as gold (Ag), silver (Au), or aluminium (Al) exhibiting superior electric conductivity, and patterned in form of a mesh.
Light electrode 114 functions as a negative pole of photoelectric conversion device 100 and may have a high opening rate. Light VL input through light electrode 114 works as an excitation source of the photosensitive dye adsorbed onto semiconductor layer 116. Accordingly, the photoelectric conversion efficiency may increase as much as light VL is input. That is, the photoelectric conversion efficiency may increase as a function of the amount of light VL that is input through light electrode 114.
A protection layer 115 may be further formed on an outer surface of grid electrode 113. That is, protection layer 115 may be formed on a surface of grid electrode 113 that is not in contact with transparent conductive film. Protection layer 115 prevents an electrode damage generated due to an erosion of grid electrode 113 when grid electrode 113 contacts and reacts with electrolyte 150. Protection layer 115 may be formed of a material that does not react with electrolyte 150. For example, protection layer 115 may be formed of a hardened resin material.
Semiconductor layer 116 may be formed by using a semiconductor material used as a contemporary photoelectric conversion device, for example, a metal oxide of metal such as cadmium (Cd), zinc (Zn), indium (In), lead (Pb), molybdenum (Mo), tungsten (W), antimony (Sb), titanium (Ti), silver (Ag), manganese (Mn), tin (Sn), zirconium (Zr), strontium (Sr), gallium (Ga), silicon (Si), and chromium (Cr). Semiconductor layer 116 may increase the photoelectric conversion efficiency by adsorbing a photosensitive dye. Semiconductor layer 116 may be formed by, for example, coating a paste in which semiconductor particles having a diameter of about 5 nm to 100 nm are dispersed, on light receiving surface substrate 110 where electrode 114 is formed. Then, a heat treatment or pressure treatment applying a predetermine heat or pressure is applied to light receiving surface substrate 110, thereby forming semiconductor layer 116.
Photosensitive dye adsorbed onto semiconductor layer 116 absorbs incident light VL passing through light receiving surface substrate 110, and thus, the electrons in the photosensitive dye are excited from a ground state to an excited state. The excited electrons are transferred to a conduction band of semiconductor layer 116 by using an electric combination between the photosensitive dye and semiconductor layer 116, pass through semiconductor layer 116, and arrive at light electrode 114. Then, the electrons are drawn to an exterior circuit through light electrode 114, forming a drive current to drive the external circuit.
The photosensitive dye may be adsorbed onto semiconductor layer 116 in a visible light ray band and may be formed of molecules causing rapid movement of electrons to semiconductor layer 116 in a light excitation state. The photosensitive dye may take any one of a liquid state, a semi-solid gel state, and a solid state. For example, a ruthenium (Ru) based photosensitive dye may be used as the photosensitive dye adsorbed onto semiconductor layer 116. Semiconductor layer 116 adsorbing the photosensitive dye may be obtained by dipping photoelectric conversion device 100 where semiconductor layer 116 is formed, in a solution including a predetermined photosensitive dye.
A redox electrolyte including a pair of an oxidant and a reductant may be used as electrolyte 150. Also, a solid electrolyte, a gel electrolyte, and a liquid electrolyte may be all used as electrolyte 150.
Opposite substrate 120 arranged to face light receiving surface substrate 110 does not particularly require transparency, but opposite substrate 120 may be formed of a transparent material to receive light VL from both sides thereof in order to increase the photoelectric conversion efficiency, or formed of the same material as that of light receiving surface substrate 110. In particular, when photoelectric conversion device 100 is installed at a structure such as a window frame and used for the purpose of building integrated photovoltaic (BIPV), both sides of photoelectric conversion device 100 may have transparency in order not to block light VL coming into a room.
Opposite electrode 124 may include a transparent conductive film 121 and a catalyst layer 122 formed on transparent conductive film 121. Transparent conductive film 121 may be formed of a material exhibiting transparency and electric conductivity, for example, TCO such as ITO, FTO or ATO. Catalyst layer 122 may be formed of a material having a reduction catalyst function to provide electrons to electrolyte 150, for example, metal such as platinum (Pt), gold (Ag), silver (Au), copper (Cu), or aluminium (Al), a metal oxide such as tin oxide (SnO2), or a carbon based material such as graphite.
Opposite electrode 124 functions as a positive pole of photoelectric conversion device 100 and as a reduction catalyst to provide electrons to electrolyte 150. The photosensitive dye adsorbed onto semiconductor layer 116 absorbs light VL to be excited. The excited electrons are drawn to the external circuit via light electrode 114. The photosensitive dye losing the electrons is reduced by collecting the electrons provided by the oxidation of electrolyte 150. The oxidized electrolyte 150 is reduced by the electrons that pass through external circuit 180 and arrive at opposite electrode 124, thereby completing the operation process of photoelectric conversion device 100.
A grid electrode 123 may be formed at opposite electrode 124, particularly on catalyst layer 122. Grid electrode 123 is introduced to reduce the electric resistance of opposite electrode 124, and provides a low-resistance current path to collect the electrons that pass through external circuit 180 and arrive to opposite electrode 124 and provide the collected electrons to electrolyte 150. For example, grid electrode 123 may be formed of a metal material such as gold (Au), silver (Ag), or aluminium (Al) exhibiting superior electric conductivity, and patterned in form of a mesh.
A protection layer 125 may be further formed on an outer surface of grid electrode 123. Protection layer 125 prevents an electrode damage generated due to the erosion of grid electrode 123 when grid electrode 123 contacts and reacts with electrolyte 150. Protection layer 125 may be formed of a material that does not react with electrolyte 150, for example, a hardened resin material.
Electrolyte injection hole 110′ is sealed by an injection hole sealing member 160. Injection hole sealing member 160 may have a pin shape having a protruding portion 165 (hereinafter referred to as an “insertion portion”) in a thicknesswise direction of light receiving surface substrate 110. That is, injection hole sealing member 160 may have an insertion portion extending in a direction perpendicular to a major surface of light receiving surface substrate 110. In detail, injection hole sealing member 160 includes a cover portion 161 covering the vicinity of an entrance 110a′ of electrolyte injection hole 110′ and an insertion portion 165 extending from cover portion 161 along electrolyte injection hole 110′ and inserted in electrolyte injection hole 110′. Cover portion 161 and insertion portion 165 constitute injection hole sealing member 160. Cover portion 161 and insertion portion 165 may be integrally formed. Cover portion 161 of injection hole sealing member 160 closes entrance end 110a′ of electrolyte injection hole 110′, and insertion portion 165 of injection hole sealing member 160 fills electrolyte injection hole 110′ in the thicknesswise direction of light receiving surface substrate 110, thereby forming a dual sealing structure to seal electrolyte 150. That is, by sealing electrolyte injection hole 110′ using injection hole sealing member 160, the dual sealing structure may be implemented by one-time assembly of injection hole sealing member 160.
In a dual sealing structure constructed as a comparative example, the sealing of electrolyte injection hole 110′ is implemented by firstly filling the inside of electrolyte injection hole 110′ by a first injection hole sealing member and secondly closing the entrance end of electrolyte injection hole 110″ by a second injection hole sealing member. In this dual sealing structure constructed as the comparative example, the numbers of the sealing members and the sealing processes increase and the structure is complicated because separate adhesion members are needed for fixing the first and second sealing members. In the embodiment shown in
An auxiliary sealing member 170 may be further provided between injection hole sealing member 160 and light receiving surface substrate 110 where electrolyte injection hole 110′ is formed. Auxiliary sealing member 170 may closely keep a seal between injection hole sealing member 160 and light receiving surface substrate 110. Electrolyte 150 filled in substrate gap G may be effectively sealed by auxiliary sealing member 170. Auxiliary sealing member 170 may be continuously and integrally formed to simultaneously cover cover portion 161 and insertion portion 165 of injection hole sealing member 160. Auxiliary sealing member 170 may include a first sealing member 171 provided between cover portion 161 and light receiving surface substrate 110 and a second sealing member 172 provided between insertion portion 165 and inner wall 110b′ of electrolyte injection hole 110′.
Cover portion 161 closely contacts the vicinity of entrance end 110a′ around electrolyte injection hole 110′ of light receiving surface substrate 110 to seal entrance end 110a′ of electrolyte injection hole 110′, thereby preventing the intrusion of foreign harmful materials through electrolyte injection hole 110′. Cover portion 161 has a cross-sectional dimension larger than that of an aperture formed by entrance end 110a′ of electrolyte injection hole 110′, and cover portion 161 surrounds the aperture and covers electrolyte injection hole 110′. In some embodiment according to the principles of the present invention, cover portion 161 may be formed to have an area larger than an area of entrance end 110a′ of electrolyte injection hole 110′. That is,
A1>A0 (1)
where A1 is the area of cover portion 161, and A0 is the area of entrance end 110a′ of electrolyte injection hole 110′. Cover portion 161 may be supported on light receiving surface substrate 110 around electrolyte injection hole 110′.
First sealing member 171 may be provided between cover portion 161 and light receiving surface substrate 110. First sealing member 171 may closely keep a seal between cover portion 161 and light receiving surface substrate 110, and may couple cover portion 161 and light receiving surface substrate 110.
Insertion portion 165 may extend by a predetermined length L along electrolyte injection hole 110′. Insertion portion 165 may have a sufficient length to prevent the intrusion of foreign harmful materials and the volatilization or leakage of electrolyte 150. For stable assembly between light receiving surface substrate 110 and opposite substrate 120, however, length L of insertion portion 165 may be designed to be not greater than a sum of thickness T of light receiving surface substrate 110 and the thickness of substrate gap G. That is,
L≦T+G (2)
Alternatively, length L of insertion portion 165 may be formed to be not greater than a sum of thickness T of light receiving surface substrate 110, thickness T1 of functional layer 118 formed on light receiving surface substrate 110, and the thickness of substrate gap G. That is,
L≦T+T1+G (3)
Substrate gap G is directly related to the height of substrate sealing member 130 disposed between light receiving surface substrate 110 and opposite substrate 120.
Second sealing member 172 may be provided between insertion portion 165 and the inner wall of electrolyte injection hole 110′. Second sealing member 172 may closely keep a seal between insertion portion 165 and inner wall 110b′ of electrolyte injection hole 110′ and may couple insertion portion 165 and inner wall 110b′ of electrolyte injection hole 110′.
In some embodiment, second sealing member 172 may extend toward substrate gap G filled with electrolyte 150. Second sealing member 172 may be pushed toward the substrate gap G from electrolyte injection hole 110′ due to the pressure of injection hole sealing member 160 during the assembly process. As a result, second sealing member 172 may extend toward substrate gap G to be formed at position 300. The sealing performance of electrolyte 150 may be improved accordingly. Second sealing member 172 contacting electrolyte 150 may have chemical resistance to electrolyte 150. Second sealing member 172 having chemical resistance may effectively restrict the leakage of electrolyte 150.
Any material capable of sealing electrolyte 150 may be sufficiently used as first and second sealing members 171 and 172. In an embodiment, first and second sealing members 171 and 172 may be formed of a material having selective flexibility according to a temperature environment. That is, first and second sealing members 171 and 172 may have sufficient flexibility to fill the gap between injection hole sealing member 160 and electrolyte injection hole 110′ by being injected into electrolyte injection hole 110′ along injection hole sealing member 160, in a high temperature environment, and may firmly adhere to the vicinity of electrolyte injection hole 110′ or inner wall 110b′ of electrolyte injection hole 110′ by being hardened in a normal operation temperature range.
In general, since photoelectric conversion device 100 operates in a temperature range of about 50° C. to 80° C., first and second sealing members 171 and 172 may include a resin based material having flexibility in a temperature range of about 80° C. to 180° C. In detail, first and second sealing members 171 and 172 may be formed of hot melt resin, or may include ethylvinylacetate, polyolefin, silicon, ionomer, and a reformed resin based material thereof. If necessary, inorganic filler such as SiO2, Al2O3, or TiO2 may be dipped in the resin based material.
Not only the temperature sensitive material exhibiting a difference in flexibility according to the temperature environment, but also a photosensitive material exhibiting a difference in flexibility according to light emission, for example, may be used as first and second sealing members 171 and 172. If necessary, a separate light hardening process to harden first and second sealing members 171 and 172 may be performed.
Any material capable of preventing intrusion of foreign harmful materials such as moisture may suffice for injection hole sealing member 160. In an embodiment, injection hole sealing member 160 may be formed of a heat conductive material to supply melting heat to first and second sealing members 171 and 172. For example, injection hole sealing member 160 may be formed of a metal material or a ceramic material. The melting heat supplied to first and second sealing members 171 and 172 via injection hole sealing member 160 makes first and second sealing members 171 and 172 in a melted or semi-melted state so as to provide flexibility.
In an embodiment, first and second sealing members 171 and 172 may be formed in an assembly process in which injection hole sealing member 160 is inserted in electrolyte injection hole 110′. That is, first and second sealing members 171 and 172 may be coated on the surface of injection hole sealing member 160 to fill between insertion portion 165 and electrolyte injection hole 110′, and between cover portion 161 and light receiving surface substrate 110.
Next, as illustrated in
Referring to
In an embodiment according to the principles of the present invention, auxiliary sealing member 170′ adhering to injection hole sealing member 160 has flexibility by applying a predetermined heat together with press pressure P. For example, the pressing and heating may be simultaneously performed by installing a heating unit 210 in press 200 that presses injection hole sealing member 160 against electrolyte injection hole 110′.
As insertion portion 165 of injection hole sealing member 160 is inserted in electrolyte injection hole 110′, an excessive amount of auxiliary sealing member 170′ adhering to the vicinity of insertion portion 165 is pushed to the outside of a limited space of electrolyte injection hole 110′ and moved toward light receiving surface substrate 110 to form first portion 171′ of auxiliary sealing member 170′. Also, a second portion 172′ of auxiliary sealing member 170′ remains and fills the inside of electrolyte injection hole 110′. First portion 171 forms a flange that extends radically outwardly from a longitudinal axis A symmetrically centred through second portion 172′.
As illustrated in
Next, as shown in
Injection hole sealing member 160 is prepared simultaneously with or immediately following the above-described processes (step 550). For example, as illustrated in
Auxiliary sealing member 170′ in a sufficient amount adheres to injection hole sealing member 160 (step S560). For example, auxiliary sealing member 170′ may be attached to the vicinity of insertion portion 165 of injection hole sealing member 160. In an embodiment according to the principles of the present invention, auxiliary sealing member 170′ in a sufficient amount may be attached to the vicinity of insertion portion 165 constituting a lower portion of injection hole sealing member 160 by dipping injection hole sealing member 160 in a bath (not shown) containing auxiliary sealing member 170′ in a liquid or paste state. The flexibility of auxiliary sealing member 170′ adhering to injection hole sealing member 160 may be maintained by supplying a predetermined heat through injection hole sealing member 160. In another embodiment according to the principles of the present invention, auxiliary sealing member 170′ may be made in a melted state or a semi-melted state having a sufficient flexibility by attaching an auxiliary sealing member 170′ in a solid state to injection hole sealing member 160 and applying a predetermined heat to auxiliary sealing member 170′ via injection hole sealing member 160.
Auxiliary sealing member 170′ adhering to injection hole sealing member 160 is heated via injection hole sealing member 160, and thus, has a sufficient flexibility to fill electrolyte injection hole 110′ with injection hole sealing member 160 in a high temperature environment.
Next, electrolyte injection hole 110′ is sealed by using the prepared injection hole sealing member 160 (step S570). First, injection hole sealing member 160 is seated in electrolyte injection hole 110′ (
In an embodiment according to the principles of the present invention, pressing and heating may be simultaneously performed as heating unit 210 is provided in press 200 for pressing injection hole sealing member 160. For facilitating heat transfer, injection hole sealing member 160 may be formed of a heat conductive material such as a metal or ceramic material.
As illustrated in
As described above, according to the one or more of the above embodiments of the present invention, a photoelectric conversion device having improved sealing performance at an electrolyte injection hole and a simplified sealing process, and a manufacturing method thereof, are provided. As the first sealing for filling the inside of the electrolyte injection hole and the second sealing for closing the entrance end of the electrolyte injection hole are provided, a dual sealing structure is implemented by one-time sealing process. Thus, the intrusion of foreign harmful materials may be prevented, the deterioration of the electrolyte may be prevented, and the leakage of the electrolyte may be effectively prevented.
It should be understood that the exemplary embodiments described therein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.
Number | Date | Country | Kind |
---|---|---|---|
10-2010-0021377 | Mar 2010 | KR | national |