Patent Application
20130000703
This Application claims priority of Taiwan Patent Application No. 100122584, filed on Jun. 28, 2011, the entirety of which is incorporated by reference herein.
1. Field of the Invention
The present invention relates to photoelectric devices, and in particular relates to complex dye-sensitized photovoltaic apparatuses.
2. Description of the Related Art
Although conventional electrochromic devices may be used as a smart window glass with energy saving and may be applied to green buildings, external power must be supplied to the electrochromic devices to change the color thereof, which consumes energy.
In recent years, the concept of energy saving has progressively gotten more attention, wherein the combination of solar cells and electrochromic devices look to be a new trend, such as applications in building-integrated photovoltaic (BIPV) systems. Without need to supply external power, the building-integrated photovoltaic system can automatically adjust color intensity of electrochromic windows according to the variation of outdoor light intensity so as to reduce indoor thermal energy, thus achieving energy saving.
The photoelectric conversion layer 130 is disposed on the conductive substrate 110, and the electrochromic layer 140 is disposed on the counter electrode 120. The hybrid electrolyte solution 150 fills the space V, wherein the hybrid electrolyte solution 150 includes an electrolyte for operation of solar cells and another electrolyte for operation of electrochromic devices, which enables oxidation-reduction reactions to occur at the photoelectric conversion layer 130 and the electrochromic layer 140.
However, because there are two electrolytes used for different purposes mixed in the hybrid electrolyte solution 150, the hybrid electrolyte solution 150 is not the best suited for both of the photoelectric conversion layer 130 and the electrochromic layer 140, which results in poor performance of photoelectric conversion and electrochromism. Furthermore, the photoelectric conversion layer 130 overlaps the electrochromic layer 140 (i.e. environmental light passes through the photoelectric conversion layer 130 and the electrochromic layer 140 sequentially), which lowers the maximum transmittance of the hybrid apparatus 100, and thus the color change of the electrochromic layer 140 is not obvious.
An embodiment of the invention provides a complex dye-sensitized photovoltaic apparatus which includes: a conductive substrate; a counter electrode opposite to the conductive substrate, wherein a space is provided between the counter electrode and the conductive substrate; a partition member disposed between the conductive substrate and the counter electrode, dividing the space into a plurality of independent chambers including at least a first chamber and a second chamber, wherein the partition member comprises an insulating material; a photoelectric conversion layer disposed on the conductive substrate in the first chamber, wherein the photoelectric conversion layer includes a porous semiconductor film and a dye absorbed on the porous semiconductor film, wherein the photoelectric conversion layer and the conductive substrate form a working electrode; a first electrolyte filled in the first chamber; and a first charge storage device or a first electrochromic solution located in the second chamber, wherein the first charge storage device includes a first charge storage layer and a second electrolyte, wherein the first charge storage layer is disposed on at least one of the conductive substrate and the counter electrode, and the second electrolyte fills the second chamber to contact with the first charge storage layer, provided that the second electrolyte is different from the first electrolyte, or the first electrochromic solution fills the second chamber to contact with the conductive substrate and the counter electrode, provided that the first electrochromic solution is different from the first electrolyte.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
It is understood, that the following disclosure provides many different embodiments, or examples, for implementing different features of the invention. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. In addition, the present disclosure may repeat reference numbers and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Furthermore, descriptions of a first layer “on,” “overlying,” (and like descriptions) a second layer, include embodiments where the first and second layers are in direct contact and those where one or more layers are interposing the first and second layers.
In the present invention, a partition member is disposed in a space provided between a conductive substrate and a counter electrode, so as to divide the space into a plurality of independent cambers, and thus a dye-sensitized solar cell device (a photoelectric conversion layer and an exclusive electrolyte thereof) and a charge storage device (a charge storage layer and an exclusive electrolyte thereof) or an electrochromic solution are disposed in the different chambers respectively. Therefore, each of the devices mentioned above has the best suited electrolyte, which improves efficiency of each of the devices, wherein the efficiency includes photoelectric conversion efficiency, electrochromic effect, and charge storage.
In one embodiment, the conductive substrate 210 may be a base 214, wherein a conductive layer 212 is deposited on a surface of the base 214. The base 214 may be a transparent base, such as a glass substrate or a plastic substrate including polyethylene terephthalate (PET), polyethylene nathphalate (PEN), polycarbonate (PC), or polyimide (PI). The conductive layer 212 includes, for example, transparent conducting oxides (TCO), such as fluorine-doped tin oxides (FTO, SnO2:F), indium tin oxides (ITO), indium zinc oxides (IZO), aluminum-doped zinc oxides (AZO) or conductive polymers, such as poly(3,4-ethylenedioxythiophene) (PEDOT), PPropOT-Et2 (poly(3,3-diethyl-3,4-dihydro-2H-thieno-[3,4-b][1,4]dioxepine)), or polyaniline. Alternatively, the conductive layer 212 may include metal (e.g. titanium, stainless steel, or aluminum) or carbon (e.g. graphene, or carbon nanotubes). In another embodiment, the conductive substrate 210 may be a substrate formed from a conductive material, such as a metal (e.g. titanium).
The counter electrode 220 is oppositely disposed to the conductive substrate 210, and a space S is provided therebetween. In one embodiment, the counter electrode 220 includes a substrate 222 and a conductive layer 224 deposited thereon. The substrate 222 may be a transparent substrate including, for example, glass or plastics, such as polyethylene terephthalate, polyethylene nathphalate, polycarbonate, or polyimide.
The conductive layer 224 includes metal, carbon, conductive polymers, transparent conductive oxides, or combinations thereof. The transparent conductive oxides are, for example, fluorine-doped tin oxides, indium tin oxides, indium zinc oxides, or aluminum-doped zinc oxides. The conductive polymers are, for example, poly(3,4-ethylenedioxythiophene) (PEDOT), PPropOT-Et2 (poly(3,3-diethyl-3,4-dihydro-2H-thieno-[3,4-b][1,4]dioxepine)), or polyaniline. In the present embodiment, a transparent conductive oxide layer 224a and a platinum layer 224b are sequentially formed on the substrate 222, wherein the platinum layer 224b has a good conductivity and does not react with the electrolyte solution, and the transparent conductive oxide layer 224a and the platinum layer 224b constitute the conductive layer 224.
Referring to
In one embodiment, the photoelectric conversion layer 240 is disposed on the conductive substrate 210 and in the first chamber S1, wherein the photoelectric conversion layer 240 and the conductive substrate 210 together constitute a working electrode W. The photoelectric conversion layer 240 includes a porous semiconductor layer 242 and a dye 244 absorbed on the porous semiconductor layer 242. As shown in
The dye 244 is a photosensitive dye including metal complexes of ruthenium, osmium, iron, illinium, platinum, or zinc, or the photosensitive dye is an organic dye, such as porphyrin, phthalocyanine, coumarin, cyanine, or hemicyanine, wherein the commonly used photosensitive dye is a ruthenium metal complex.
Commercially available ruthenium metal complexes include a N3 dye, a N712 dye, a N719 dye, or a N749 dye. The chemical formula of the N3 dye is cis-di(thiocyanato)-bis(2,2′-bipyridyl-4,4-dicarboxylic acid)-ruthenium (II). The chemical formula of the N712 dye is (Bu4N) 4-[Ru (dcbpy) 2 (NCS) 2], wherein Bu4N is tetrabutyl-ammonium, and dcbpy H2 is 2,2′-bipyridyl-4,4′-dicarboxylic acid. The chemical formula of the N719 dye is cis-di(thiocyanato)-bis(2,2′-bipyridyl-4-carboxylate-4′-carboxylic acid)-ruthenium (II). The chemical formula of the N749 dye is (4,4′,4′-tricarboxy-2,2′:6′,2′-terpyridine) ruthenium (II).
The first electrolyte solution 250 fills the first chamber S1 to contact with the photoelectric conversion layer 240. The first electrolyte solution 250 includes redox pairs, such as the redox pairs constituted by iodide ions (I−) and triiodide ions (I3−). The first electrolyte solution 250 may be prepared, for example, by dissolving ionic compounds suitable to form the redox pairs in the solvent.
The ionic compounds include halides, such as iodides or bromides. Specifically, metal iodide salts or metal bromide salts may be used. The ionic compound capable of forming iodide ions (E) and triiodide ions (I3−) is preferred, such as LiI, KI, and KI3. In one embodiment, LiI and I2 are dissolved in the solvent to form a I−/I3− redox pair. The solvent is, for example, methoxypropionitrile (MPN), acetonitrile (AN), or γ-butyrolactone (GBL).
In one embodiment, the first electrolyte solution 250 has 0.1M LiI dissolved in acetonitrile, a 0.05M I2, a 0.6M 1,2-dimethyl-3-propylimi-dazolium iodide (DMPII), and a 0.5M 4-tert-butylpyridine (TBP).
The first charge storage device 260 is located in the second chamber S2, wherein the first charge storage device 260 includes a first charge storage layer 262 and a second electrolyte solution 264. The first charge storage layer 262 is disposed on at least one of the conductive substrate 210 and the counter electrode 220. In other words, according to materials, properties, or uses, the first charge storage layer 262 may be disposed on one of the conductive substrate 210 and the counter electrode 220, or on both the conductive substrate 210 and the counter electrode 220. The second electrolyte solution 264 fills the second chamber S2 to contact with the first charge storage layer 262, wherein the second electrolyte solution 264 enables an electrochromic reaction or a charge storage reaction to occur at the first charge storage layer 262 of the first charge storage device 260, and the material of the second electrolyte solution 264 is different from that of the first electrolyte solution 250 of the dye-sensitized solar cell.
For example, in one embodiment, the first charge storage device 260 is a capacitor device, and the first charge storage layer 262 is a capacitor electrode. In this case, the first charge storage layer 262 may be disposed on the conductive substrate 210 (not shown), the counter electrode 220 (as shown in
The capacitor electrode includes, for example, conductive polymers, carbon materials, or other suitable capacitor materials. The conductive polymers are, for example, poly(3,4-ethylenedioxythiophene) (PEDOT), PPropOT-Et2 (poly(3,3-diethyl-3,4-dihydro-2H-thieno-[3,4-b][1,4]dioxepine)), or polyaniline. The carbon materials are, for example, activated carbon, carbon nanotubes, or graphene. If the first charge storage layer 262 is a capacitor electrode, the second electrolyte solution 264 is, for example, a sulfuric acid solution.
In another embodiment, the first charge storage device 260 is an electrochromic device, and the first charge storage layer 262 is an electrochromic material layer. In this case, the first charge storage layer 262 may be disposed on the conductive substrate 210 (not shown), the counter electrode 220 (as shown in
The electrochromic material layer may include conductive polymers, organic molecules, inorganic materials, or other suitable electrochromic materials. The conductive polymers are, for example, poly(3,4-ethylenedioxythiophene) (PEDOT), PPropOT-Et2 (poly(3,3-diethyl-3,4-dihydro-2H-thieno-[3,4-b][1,4]dioxepine)), polyaniline, or polypyrrole. The organic molecules are, for example, viologen (1,1′-disubstituted-4,4′-bipyridilium). The inorganic materials are, for example, Prussian blue (iron(III) hexacyanoferrate), WO3, or V2O5.
In one embodiment, the material of the electrochromic material layer mentioned above is the same as that of the conductive layer 224, and they are both conductive polymers, such as poly(3,4-ethylenedioxythiophene) (PEDOT), PPropOT-Et2 (poly(3,3-diethyl-3,4-dihydro-2H-thieno-[3,4-h][1,4]dioxepine)), or polyaniline.
Furthermore, if the first charge storage layer 262 is an electrochromic material layer, the second electrolyte solution 264 includes, for example, a 1.0M tetrabutylammonium bromide (TBABr) dissolved in 3-methoxypropionitrile, 0.1M LiClO4, and 0.004M Br2.
It should be noted that, because the partition member 230 separates the first electrolyte solution 250 from the second electrolyte solution 264 of the first charge storage device 260 in the embodiment, the most suitable first electrolyte solution 250 and the most suitable second electrolyte solution 264 may be chosen for the photoelectric conversion layer 240 and the first charge storage layer 262 respectively, thereby effectively improving performance of the photoelectric conversion layer 240 and the first charge storage layer 262.
Furthermore, because the photoelectric conversion layer 240 and the first charge storage device 260 are located in different chambers respectively, the photoelectric conversion layer 240 does not overlap with the first charge storage device 260, which may effectively raise the maximum transmittance of the complex dye-sensitized photovoltaic apparatus 200, thereby improving the color change effect of the electrochromic layer.
In one embodiment, the complex dye-sensitized photovoltaic apparatus 200 may further include a high-conductivity structure L. A portion of the high-conductivity structure L is on the conductive substrate 210 and sandwiched between the partition member 230 and the conductive substrate 210, and another portion of the high-conductivity structure L is on the counter electrode 220 and sandwiched between the partition member 230 and the counter electrode 220.
Specifically, the partition member 230 covers the high-conductivity structure L to prevent the high-conductivity structure L from contacting with the first electrolyte solution 250 and the second electrolyte solution 264, wherein the high-conductivity structure L has an electric conductivity higher than the conductive substrate 210 or the counter electrode 220. The high-conductivity structure L includes silver, copper, aluminum, copper aluminum alloys, or other materials with good conductive properties. The high-conductivity structure L may effectively collect the charges produced by the photoelectric conversion layer 240, and uniformly conduct the charges to the first charge storage device 260.
One of the manufacturing methods of the complex dye-sensitized photovoltaic apparatus 200 mentioned above is described as follows, and the experiment parameters and the material of the devices described below are merely examples and are not intended to be limiting.
Then, the conductive substrate with the titania paste layer is disposed in an oven, for example, at 450° C. to be sintered, so as to form TiO2 particle layer on the conductive substrate. Then, the conductive substrate with TiO2 particle layer is dipped in a solution containing dye to absorb the dye, and the preferred absorption time is 24 hours, wherein the dye includes, for example, N719 from Solaronix. The TiO2 particle layer with the dye absorbed thereon may serve as a photoelectric conversion layer 240.
Then, referring to
Then, an electroplating solution used to electroplate an electrochromic material layer is prepared, wherein the electroplating solution contains a 10 mM 3,3-diethyl-3,4-dihydro-2H-thieno-[3,4-b][1,4]dioxepine (PropOT-Et2) monomer dissolved in acetonitrile and a 100 mM LiClO4.
Then, a mask is formed on the platinum layer 224b to shield a portion of the platinum layer 224b which is not to be electroplated. Then, the counter electrode is disposed in an electroplating solution to perform an electroplating process, wherein the electroplating conditions include, for example: depositing a conductive polymer film on the platinum layer 224b at 1.2V (vs. Ag/Ag+) to serve as a first charge storage layer 262 (i.e. the electrochromic material layer), wherein the electrical quantity of the electroplating process is 40 mC/cm2. Then, the mask is removed.
Then, referring to
Then, referring to
Then, an electrolyte solution (the first electrolyte solution 250) used in dye-sensitized solar cells and an electrolyte (the second electrolyte solution 264) used in electrochromic devices are injected into the first chamber S1 and the second chamber S2 respectively, and then the injection holes of the first chamber S1 and the second chamber S2 are sealed by encapsulating materials.
As shown in
In this case, the complex dye-sensitized photovoltaic apparatus 200 serves as, for example, a smart window, and the photoelectric conversion layer 240 may be on the periphery of the window. If environmental light illuminates the photoelectric conversion layer 240, the photoelectric conversion layer 240 may produce a current to change the color of the first charge storage device 260 in the center area of the window, which adjusts indoor brightness and temperature.
Specifically, the positions of the first chamber S1 and the second chamber S2 may be exchanged, such that the first chamber S1 accommodating the photoelectric conversion layer 240 is located in the center area A, and the second chamber S2 accommodating the electrochromic device is located in the peripheral area B.
The first electrochromic solution 270 includes electrochromic materials and solvents. The electrochromic materials are, for example, methyl viologen, ethyl viologen, heptyl viologen (HV), benzyl viologen, propyl viologen, dimethylphenazine, phenylene diamine, N,N,N′,N′-tetramethyl-1,4-phenylenediamine (TMPD), and redox potentials thereof are both less than 3V. The solvent of the first electrochromic solution 270 is, for example, propylene carbonate, glycol carbonate, γ-butyrolactone, acetonitrile, tetrahydrofuran, or N-methylpyrrolidinone (NMP).
Specifically, the positions of the first chamber S1 and the second chamber S2 may be exchanged, such that the first chamber 51 accommodating the photoelectric conversion layer 240 is located in the center area A, and the second chamber S2 accommodating the first electrochromic solution 270 is located in the peripheral area B.
The third chamber S3 may accommodate a second charge storage device 280. The second charge storage device 280 includes a second charge storage layer 282 and a third electrolyte solution 284, wherein the second charge storage layer 282 may be optionally disposed on the conductive substrate 210, the counter electrode 220, or both the conductive substrate 210 and the counter electrode 220 (as shown in
The use of the second charge storage device 280 may be similar to the use of the first charge storage device 260 mentioned above, and the materials of the second charge storage layer 282 and the third electrolyte solution 284 may be similar to the materials of the first charge storage layer 262 and the second electrolyte solution 264 mentioned above, thus, reference may be made thereto. The second charge storage device 280 may be the same as or different from the first charge storage device 260.
In one embodiment, the first charge storage device 260 is an electrochromic device, the first charge storage layer 262 is an electrochromic material layer, the second charge storage device 280 is a capacitor device, and the second charge storage layer 282 is a capacitor electrode.
Although
In the complex dye-sensitized photovoltaic apparatus used in the test, the conductive substrate included fluorine-doped tin oxides/glass, the counter electrode included fluorine-doped tin oxides/glass, the photoelectric conversion layer included titanium dioxides, and the first electrolyte solution included 0.1M LiI, 0.05M I2, 0.6M 1,2-dimethyl-3-propylimi-dazolium iodide (DMPII), and 0.5M 4-tert-butylpyridine (TBP) dissolved in methoxypropionitrile.
The measuring scan voltage range of the Keithley photoelectric conversion layer 2400 was from 0V to −0.8V. The scan rate was 100 mV/s. The delay time was 100 ms. The current produced by the dye-sensitized solar cell at each voltage was recorded to produce the I-V curve diagram. It could be known from the I-V curve diagram that, the open-circuit voltage (V∝) was 0.68V, and the short-circuit current density (Jsc) was 13.7 mA/cm2. Meanwhile, by calculating the test result, the fill factor (FF) was 0.55, and the photoelectric conversion efficiency (η) was 5.2%.
In the complex dye-sensitized photovoltaic apparatus used in the test, the conductive substrate included fluorine-doped tin oxides/glass, the counter electrode included fluorine-doped tin oxides/glass, the first charge storage layer (the electrochromic layer) included PPropOT-Et2 (poly(3,3-diethyl-3,4-dihydro-2H-thieno-[3,4-b][1,4]dioxepine)), and the second electrolyte solution included 1.0M tetrabutylammonium bromide (TBABr), 0.1M LiClO4, and 0.004M Br2 dissolved in 3-methoxypropionitrile.
The test results are described as follows. The bleaching time (τb) was 2.11 s. The coloring time (τd) was 1.27 s. The transmittance (Tb) in the bleaching condition was 57.9%. The transmittance (Td) in the coloring condition was 12.4%. The transmittance difference (ΔT) between the bleaching condition and the coloring condition was 45.5%.
In view of the foregoing, in the present invention, the partition member was disposed between the conductive substrate of the working electrode and the counter electrode, so as to form a plurality of independent chambers, such that the dye-sensitized solar cell device and the charge storage device was disposed in different chambers respectively. Thus, each device may be equipped with the most suitable electrolyte, which avoids the conventional problems where the electrolytes used for different purposes are mixed and interfere with each other. Thus, the performance of each device in the present invention is improved.
Furthermore, in the present invention, the different devices are disposed in the different independent chambers respectively, which avoids the conventional problems where the photoelectric conversion layer overlaps with the electrochromic layer. Thus, the maximum transmittance of the complex dye-sensitized photovoltaic apparatus of the present invention may be effectively risen, which improves the color change effect of the electrochromic layer.
While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
| Number | Date | Country | Kind |
|---|---|---|---|
| TW100122584 | Jun 2011 | TW | national |
