TWM486145U - Dye-sensitized solar cell - Google Patents

Abstract

A dye-sensitized solar cell is provided. The dye-sensitized solar cell includes a working electrode, a counter electrode on the working electrode and an electrolyte between the working electrode and the counter electrode. The working electrode includes a transparent plate, a porous semiconductor layer on the transparent conductive plate and a dye in the porous semiconductor layer.

Description

Dye sensitized solar cell

This creation relates to an optoelectronic device and in particular to a dye-sensitized solar cell.

In the 21st century, where energy is about to be announced, the concept of sustainable use of green energy has emerged, so the development of various green energy sources is the main research goal. Countries are actively developing green energy sources such as solar energy, geothermal energy, wind power generation, hydropower generation and biomass energy to replace limited resources and reduce environmental pollution. In recent years, dye-sensitized solar cells in solar energy sources have been developed.

Dye-sensitized Solar Cell (DSSC) has the advantages of simple process, low cost, light weight, convenient carrying and flexibility, and its research and development and market development have great potential.

In 1991, Swiss scientist M.Grätzel published a porous titanium dioxide film to adsorb a single molecule dye layer with a photoelectric conversion efficiency of 7.1% to 7.9%. It was found that the dye molecules of such base metal derivatives can absorb the sun in the near full wavelength range. Light, after research, the best photoelectric conversion efficiency can reach 11.18%. In 2003, M. Grätzel published the use of ruthenium metal pyridine complex (N719) dye as a dye for wet dye-sensitized solar cells with photoelectric conversion efficiency in a standard solar analog light source. (AM 1.5) The measurement can be obtained by 10.58%. In 2011, K.C.Ho used commercially available organometallic dyes N719, Black dye and element 114 (Flerovium, FL) organic dyes to prepare dye-sensitized solar cells with an optimum efficiency of 5.10%. Recently, ZTE University, Jiaotong University and the Swiss Federal Institute of Technology in Lausanne have collaborated to study the purple molecules to prepare the latest organic photosensitive materials with the concept of artificial chlorophyll, which can effectively absorb the visible and near-infrared wavelengths of sunlight and convert light energy into electrical energy. Its photoelectric conversion efficiency can reach 13.1%.

Republic of China New Patent No. M436222 "Dye-sensitized solar energy Improvement of battery structure for electrode and its application" discloses a dye-sensitized solar working electrode and an improved battery structure thereof, and a conductive unit formed by combining a semiconductor material such as titanium dioxide and a dye molecule on a conductive substrate to form a work The electrode is further composed of a second conductive substrate, two working electrodes, and an electrolyte layer, a catalyst layer and the like to constitute a dye-sensitized solar cell. The conductive unit mainly has a plurality of electrically conductive layers of semiconductor materials of different particle sizes. The semiconductor material comprises at least a first semiconductor material having a material particle diameter of less than 10 nm and a second semiconductor material having a material diameter of 10 to 50 nm and a third semiconductor. The material has a particle size of 50-100 nm, so that the semiconductor materials can be stacked or blended into one body independently, thereby enhancing the transmission of electrons and improving the photoelectric conversion efficiency of the dye-sensitized solar cell.

The Republic of China new patent No. M380573 "Working electrode and its application The prepared dye-sensitized solar cell discloses a working electrode for a dye-sensitized solar cell, and the working electrode comprises a first conductive substrate and a conductive unit disposed on the first conductive substrate. The conductive unit comprises a conductive oxide film, a plurality of oxide nanotubes disposed on a side of the conductive oxide film away from the first conductive substrate, and a dye adsorbed on the surface of the oxide nanotube. The above new type also provides a response A dye-sensitized solar cell produced by using the above working electrode. The above novel dye-sensitized solar cell comprises a working electrode as described above, a pair of electrodes, and an electrolyte. The counter electrode comprises a second conductive substrate and an inert metal layer disposed on the second conductive substrate, the electrolyte being located between the working electrode conductive unit and the counter electrode inert metal layer. The working electrode and the dye-sensitized solar cell can effectively improve the dye adsorption amount of the dye-sensitized solar cell and the ability to absorb solar energy, and suppress the conductivity by using a special double-layer conductive strip, that is, an oxide nano tube and a conductive oxide film. The recombination effect of electrons and holes in the unit, thereby improving the photoelectric conversion efficiency of the dye-sensitized solar cell.

Republic of China New Patent No. M375974 "Work with double-layer film As an electrode and a dye-sensitized solar cell produced by the same, a working electrode is used for a dye-sensitized solar cell, and the working electrode comprises a first conductive substrate and a conductive unit disposed on the first conductive substrate. The conductive unit comprises a porous zinc oxide film disposed on the first conductive substrate, a porous titanium dioxide film disposed on a side of the porous zinc oxide film away from the first conductive substrate, and adsorbed on the porous titanium dioxide film. Dye. The above novel also provides a dye-sensitized solar cell produced by applying the above working electrode.

The embodiment of the present invention discloses a dye-sensitized solar cell comprising: a working electrode; an auxiliary electrode on the working electrode; and an electrolyte between the working electrode and the auxiliary electrode, wherein the working electrode comprises: a transparent a conductive plate; a porous semiconductor layer on the transparent conductive plate; and a dye located in the porous semiconductor layer.

The dye-sensitized solar cell of the present invention has a simple process and preparation Time saving and environmental advantages.

The above and other objects, features, and advantages of the present invention will become more apparent and understood.

10‧‧‧Dye-sensitized solar cells

11‧‧‧ electrolyte

20‧‧‧Working electrode

21, 24‧‧‧ Transparent conductive plate

21a, 24a‧‧‧ Transparent substrate

21b, 24b‧‧‧ transparent conductive layer

22‧‧‧Porous semiconductor layer

23‧‧‧D dyes

30‧‧‧Auxiliary electrode

31‧‧‧ Catalytic layer

40‧‧‧ Heterogeneous Interface Impedance Measurement Architecture

41‧‧‧Wire

42‧‧‧Electrochemical Impedance Analyzer

50‧‧‧ equivalent circuit model

C2‧‧‧Chemical capacitance between working electrode and electrolyte

Ohmic inductance due to inductance effect between L1‧‧‧ wire and transparent conductive plate

Q1‧‧‧ Double layer capacitance between auxiliary electrode and electrolyte

R1‧‧‧ ohmic resistance of wires and transparent conductive plates

R2‧‧‧ Charge transfer resistance between auxiliary electrode and electrolyte

R3‧‧‧ Charge transfer resistance between working electrode and electrolyte

W4‧‧‧Warberg resistance of electrolyte diffused into the porous semiconductor layer

Fig. 1 is a schematic cross-sectional view showing a dye-sensitized solar cell according to an embodiment of the present invention.

Fig. 2 is a schematic view showing the structure of the hetero interface impedance of the dye-sensitized solar cell according to an embodiment of the present invention.

Fig. 3 is an equivalent circuit model of a dye-sensitized solar cell according to an embodiment of the present invention.

Figure 4 depicts the actual measurement and the Nyquist plot obtained by an equivalent circuit model simulation.

Figure 5A depicts a Nyquist plot of a dye-sensitized solar cell having a porous semiconductor layer formed at different spin coating speeds in accordance with some embodiments of the present teachings.

Fig. 5B is an enlarged view corresponding to the portion of the broken line frame of Fig. 5A.

Figure 6A depicts a Nyquist plot of a dye-sensitized solar cell having a porous semiconductor layer formed at different annealing temperatures, in accordance with some embodiments of the present teachings.

Fig. 6B is an enlarged view corresponding to the portion of the broken line frame of Fig. 6A.

The dye-sensitized solar cell of the present embodiment will be described below. However, it is readily understood that the examples provided by the present invention are only intended to illustrate the creation and use of the present invention in a particular manner and are not intended to limit the scope of the present invention. In the drawings and the description of the present embodiments, the same reference numerals are used to refer to the same or similar parts.

Referring to FIG. 1, a cross-sectional view of a dye-sensitized solar cell 10 according to an embodiment of the present invention is shown. In the present embodiment, the dye-sensitized solar cell 10 includes a working electrode 20, an auxiliary electrode 30 on the working electrode 20, and an electrolyte 11 between the working electrode 20 and the auxiliary electrode 30. The working electrode 20 includes a transparent conductive plate 21, a porous semiconductor layer 22 on the transparent conductive plate 21, and a dye 23 located in the porous semiconductor layer 22.

The transparent conductive plate 21 includes a transparent substrate 21a and a transparent conductive layer 21b. In the present embodiment, the transparent substrate 21a may be glass, a flexible transparent substrate or any substrate material suitable for dye-sensitized solar cells. The transparent conductive layer 21b may be indium tin oxide (ITO), fluorine-doped tin oxide (FTO), or any suitable transparent conductive material. In the present embodiment, the thickness of the transparent conductive plate 21 is between 175 μm and 2000 μm.

The porous semiconductor layer 22 includes titanium oxide, zinc oxide, or any semiconductor having a matching energy level with the oxidation-reduction potential of the dye 23 and the electrolytic solution 11 and easily adsorbing the dye 23. In the present embodiment, the surface of the porous semiconductor layer 22 may have a high specific surface area, which contributes to the improvement of the adsorption of the dye 23. In the present embodiment, the thickness of the porous semiconductor layer 22 is between 8 μm and 20 μm.

Dye 23 includes an organic ruthenium metal complex, such as N3 (Ruthenium-535), Z907 (Ruthenium 520-DN), N719 (Ruthenium 535-bis TBA) or N749 (Ruthenium 620-1H3 TBA), which absorbs light and excites electrons. In the present embodiment, the dye 23 has the following characteristics: (1) can be closely adsorbed to the porous semiconductor layer 22, and quickly reaches the adsorption equilibrium and is not easy to fall off; (2) the absorption spectrum of the dye 23 is well matched with the solar spectrum; (3) The oxidation state and the excited state of the dye 23 have high stability and activity; (4) the excited state of the dye 23 is long, and the charge transport efficiency is high; (5) the dye 23 has a match with the porous semiconductor layer 22. The redox potential; (6) The dye 23 has a relatively low potential in the redox process, which can reduce the electron transfer energy loss between the primary and secondary.

The electrolyte 11 includes a redox couple, an additive, and a solvent (not shown). Redox couple may include an I3- / I ^- or any electrolyte suitable for a dye-sensitized solar cell of the redox couple. Additives may include sodium iodide (NaI), lithium iodide (LiI), 1-propyl-2,3-dimethylimidazolium iodide, DMPII) or 4-tert-butylpyridine (TBP), which helps reduce the probability of electron hole recombination and improve electron transfer rate. The solvent may include acetonitrile (Acetonitrile), 3-methoxypropionitrile (MPN), and Propylene carbonate (PC). In the present embodiment, the electrolyte 11 has the following characteristics: (1) the redox of the electrolyte 11 facilitates efficient regeneration of the redox potential of the dye 23; (2) the electrolyte 11 has high solubility, which ensures sufficient electron concentration and Avoid diffusion resistance; (3) Electrolyte 11 has a high diffusion coefficient, which can facilitate the occurrence of mass transfer; (4) Electrolyte 11 has no absorption peak in the visible light band, which can prevent incident light from being absorbed by electrolyte 11; (5) Electrolyte 11 (6) The electrolyte 11 has a high-speed redox rate, which facilitates electron transfer; and (7) the electrolyte 11 does not corrode the working electrode 20 and the auxiliary electrode 30.

The auxiliary electrode 30 includes a transparent conductive plate 24 and is located at a transparent conductive A catalytic layer 31 on the surface of the plate 24. In the present embodiment, the transparent conductive plate 24 includes a transparent substrate 24a and a transparent conductive layer 24b. The material and thickness of the transparent substrate 24a and the transparent conductive layer 24b may be the same or similar to the transparent substrate 21a and the transparent conductive layer 21b, and will not be described herein.

The catalytic layer 31 comprises platinum, graphene, carbon nanotubes, nickel or any other A material that accelerates the redox reaction of the electrolytic solution 11. In the present embodiment, the thickness of the catalytic layer 31 is between 100 nm and 300 nm.

Hereinafter, a manufacturing of the dye-sensitized solar cell 10 of Fig. 1 will be described. method. However, it is to be understood that the dye-sensitized solar cell 10 of the present invention is not limited to being manufactured in the following manner.

Manufacturing of working electrode 20

First, a transparent conductive plate 21 (e.g., fluorine-doped tin oxide glass) is provided, and the transparent conductive plate 21 is washed with deionized water. Next, the transparent conductive plate 21 is placed in an oven to evaporate moisture on the surface of the transparent conductive plate 21.

Mixing a semiconductor powder (eg, titanium dioxide or zinc oxide powder), a dispersant (eg, 2,4-pentane ketone), a surfactant (eg, Triton X-100 (Cl ₄ H) ₂₂ O(C ₂ H ₄ O) _n ) and a solvent (e.g., deionized water) to obtain a coating colloid. In this embodiment, the mixing ratio of the above components may be 1:3:100. Then, by spin-coating, Radio Frequency Sputtering Method, Screen-printing, Blade-coating or any suitable method The coating colloid is formed on the transparent conductive plate 21 to form the porous semiconductor layer 22. In the present embodiment, the porous semiconductor layer 22 having an effective area of 0.8 cm × 0.8 cm can be formed on the transparent conductive plate 21.

The transparent conductive plate 21 having the porous semiconductor layer 22 described above is placed Baking in an oven at 100 ° C for 10 minutes, and annealing in an annealing furnace at 350-650 ° C for 30 minutes to remove the organic matter remaining on the surface of the porous semiconductor layer 22 and increase the adhesion of the porous semiconductor layer 22, thereby improving the film. Quality and improved conductivity.

An appropriate amount of dye powder (e.g., N3 dye (Ruthenium-535, N3) powder) is taken and added to an 80 mL ethanol solution to obtain a dye 23 having a concentration of 3 × 10 ^-4 M. Next, the dye is oscillated by ultrasonic waves for 15 minutes, and the porous semiconductor layer 22 on the transparent conductive plate 21 is placed in the dye 23 at a temperature of 25 ° C to 75 ° C for 1 hour to 24 hours to complete the manufacture of the working electrode 20. .

Manufacture of electrolyte 11

Take 0.5M lithium iodide (LiI), 0.6M metal iodide (1-propyl-2,3-dimethylimidazolium iodide, DMPII), 0.5M 4-tert-butylpyridine (4-Tert-Butylpyridine) , TBP) and 0.05 M of iodine (Iodine, I ₂ ) were dissolved in 15 mL of 3-methoxypropionitrile (MPN) and ultrasonically shaken for 10 minutes to complete the production of the electrolyte 11.

Manufacture of auxiliary electrode 30

First, a transparent conductive plate 24 is provided. Then, the catalytic layer 31 is formed on the transparent conductive plate 22 by a radio frequency sputtering method, a screen printing method, a knife coating method, a spin coating method or any appropriate method, which may be platinum, graphene or nano carbon. The tube, nickel or any material which accelerates the redox reaction of the catalytic electrolyte 11 completes the manufacture of the auxiliary electrode 30.

Package of dye-sensitized solar cell 10

The auxiliary electrode 30 to the two drilled holes, and to a thermoplastic film (e.g., DuPont ^TM Surlyn ^® 1706) encapsulation of the working electrode 20 and the auxiliary electrode 30. Next, the electrolyte 11 is injected into the small holes to complete the manufacture of the dye-sensitized solar cell 10.

Figure 2 illustrates the difference between the dye-sensitized solar cells 10 Schematic diagram of the structure 40 of the qualitative interface impedance. Referring to FIG. 2, the working electrode 20 and the auxiliary electrode 30 of the dye-sensitized solar cell 10 are respectively connected by wires 41 to an electrochemical impedance analyzer (BioLogic SP-150, France) 42. In the above architecture 40, the resistance, capacitance and inductance of the dye-sensitized solar cell 10 at the heterojunction can be simulated by an impedance simulation software (Z-View) via an equivalent circuit model 50 (see Fig. 3). A Nyquist spectrogram is obtained (see Figures 4, 5A-5B, 6A-6B). Through the above measurement architecture 40, the resistance, capacitance and inductance changes at the heterogeneous interface inside the dye-sensitized solar cell can be effectively simulated and the battery structure can be optimized.

In this embodiment, the Nyquist frequency of the 4th, 5A-5B, and 6A-6B diagrams The spectrum is obtained by applying a small amplitude sine wave potential (10 mV) with a frequency range of 50 mHz to 1 MHz or a current as a disturbance signal and applying a positive bias voltage of 0.7 V. The impedance spectrum at the heterojunction where the electron transmission speed is faster will appear in the high frequency region, and the impedance spectrum at the heterojunction where the electron transmission speed is slow will appear in the low frequency region. Therefore, the dye sensitization can be known from the Nyquist spectrogram. Solar cell 10 includes several different heterojunction junctions.

Referring to Figure 3, L1 represents the cause of the conductor 41 and the transparent conductive plate 21/24. The Ohmic Inductance generated by the inductance effect, R1 represents the Ohmic Resistance of the wire 41 and the transparent conductive plate 21/24, and R2 represents the charge-transfer resistance between the auxiliary electrode 30 and the electrolyte 11 (Charge-transfer Resistance) R3 represents the charge transfer resistance between the working electrode 20 and the electrolyte 11, and W4 represents the Warburg resistance of the electrolyte 11 diffused to the porous semiconductor layer 22 (Warburg) Resistance), Q1 represents a double-layer capacitance between the auxiliary electrode 30 and the electrolyte 11, and C2 represents a chemical capacitance between the working electrode 20 and the electrolyte 11 (Chemical Capacitance).

Figure 4 depicts the actual measurement of a dye-sensitized solar cell and borrowing A comparison of the Nyquist spectrograms simulated by the equivalent circuit model 50. As shown in Fig. 4, the simulated Nyquist spectrum is similar to the actual measured Nyquist spectrum, which proves that the equivalent circuit model provided by this creation is similar to the actual dye-sensitized solar cell structure. It can effectively simulate the change of resistance, capacitance and inductance of the dye-sensitized solar cell at the heterojunction, thereby optimizing the battery structure.

Table 1 discloses electrical parameter measurements of dye-sensitized solar cells 10 having porous semiconductor layers 22 formed at different spin coating speeds in accordance with some embodiments of the present teachings. In Table 1, V _OC , J _SC , FF, η represent Open-circuit Voltage, Short-circuit Current Density, Fill Factor, and Photoelectric Conversion Efficiency, respectively. ).

As shown in Table 1, when the spin coating speed is increased, its spin coating is separated. The cardiac action will be enhanced to reduce the thickness of the porous semiconductor layer 22, causing a current The density is reduced. However, as the rotation speed decreases, the angle and profile measuring instrument finds that fine cracks are formed on the surface of the film, which causes the uniformity of the surface of the film to decrease, resulting in a decrease in the open circuit voltage. From the measurement results of Table 1, it is known that the embodiment in which the spin coating rotation speed is 2000 rpm has the optimum electrical parameters.

Table 2 discloses some embodiments according to the present creation, having different spin coatings The impedance simulation value of the dye-sensitized solar cell 10 of the porous semiconductor layer 22 formed at the cloth rotation speed. Fig. 5A is a Nyquist plot obtained from the data simulation of Table 2, and Fig. 5B is an enlarged view corresponding to the portion of the broken line frame of Fig. 5A. As is apparent from the above simulation results, when the number of rotations of the porous semiconductor layer 22 is slowed down, the thickness of the porous semiconductor layer 22 tends to increase, and the amount of adsorption of the dye 23 on the porous semiconductor layer 22 is increased, so that the short-circuit current density is increased. Thus, the charge transfer resistance R3 at the interface between the working electrode 20 and the electrolyte 11 is lowered.

Table 3 discloses some embodiments according to the present creation, having different annealing temperatures The electrical parameter of the dye-sensitized solar cell 10 of the porous semiconductor layer 22 formed under the degree number.

As shown in Table 3, when the annealing temperature is increased from 350 ° C to 550 ° C, short The path current density and the photoelectric conversion efficiency are improved, and the grain size of the porous semiconductor layer 22 and the surface roughness of the porous semiconductor layer 22 are increased to have a light scattering effect and the light absorption amount of the dye 23 is increased. When the annealing temperature is increased from 650 ° C to 750 ° C, the rutile crystal phase has a lower energy level, which makes the electrons easily fall back to the valence band and cause electron hole recombination, resulting in a decrease in the short-circuit current density. From the measurement results of Table 3, it is understood that the embodiment having an annealing temperature of 550 ° C has the best electrical parameters.

Table 4 discloses some embodiments according to the present creation, having different annealing temperatures The impedance simulation value of the dye-sensitized solar cell 10 of the porous semiconductor layer 22 formed under the degree. Fig. 6A is a Nyquist diagram obtained by simulation based on the data of Table 4, and Fig. 6B is an enlarged view corresponding to a portion of the broken line frame of Fig. 6A. From the above simulation results, it is known that the impedance value in the intermediate frequency region is related to the incident photon amount of the porous semiconductor layer 22. After annealing, the particles on the porous semiconductor layer 22 have the effect of reflecting incident photons, so that the semicircular impedance of the intermediate frequency interface is obtained. Decrease and significantly increase the short circuit current. When the annealing temperature is increased from 350 ° C to 550 ° C, the surface roughness of the film of the porous semiconductor layer 22 is increased, so that the amount of adsorption of the dye 23 is increased.

Table 4 has the dyeing of the porous semiconductor layer 22 formed at different annealing temperatures.

Although the present invention has been disclosed in the above preferred embodiments, it is not intended to limit the present invention, and any person skilled in the art can make any changes and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this creation is subject to the definition of the scope of the patent application attached.

10‧‧‧Dye-sensitized solar cells

11‧‧‧ electrolyte

20‧‧‧Working electrode

21, 24‧‧‧ Transparent conductive plate

21a, 24a‧‧‧ Transparent substrate

21b, 24b‧‧‧ transparent conductive layer

22‧‧‧Porous semiconductor layer

23‧‧‧D dyes

30‧‧‧Auxiliary electrode

31‧‧‧ Catalytic layer

Claims (11)

A dye-sensitized solar cell comprising: a working electrode; an auxiliary electrode on the working electrode; and an electrolyte between the working electrode and the auxiliary electrode, wherein the working electrode comprises: a first transparent conductive a plate; a porous semiconductor layer on the first transparent conductive plate; and a dye located in the porous semiconductor layer. The dye-sensitized solar cell of claim 1, wherein the first transparent conductive plate comprises a transparent substrate and a transparent conductive layer. The dye-sensitized solar cell of claim 2, wherein the transparent substrate comprises a glass or a flexible transparent substrate, and the transparent conductive layer comprises indium tin oxide or fluorine-doped tin oxide. The dye-sensitized solar cell of claim 1, wherein the porous semiconductor layer comprises titanium dioxide or zinc oxide. The dye-sensitized solar cell of claim 1, wherein the dye comprises an organic ruthenium metal complex. The dye-sensitized solar cell of claim 1, wherein the electrolyte comprises a redox couple, an additive, and a solvent. The dye-sensitized solar cell of claim 6, wherein the redox pair comprises I ^- /I ₃ ^- . The dye-sensitized solar cell of claim 6, wherein the solvent comprises acetonitrile, methoxypropionitrile or a combination thereof. The dye-sensitized solar cell of claim 6, wherein the additive comprises sodium iodide, lithium iodide, 4-tert-butylpyridine, 1,2-dimethyl-3-propylimidonate An azole salt or a combination of the above. The dye-sensitized solar cell of claim 1, wherein the auxiliary electrode comprises a second transparent conductive plate and a catalytic layer on the second transparent conductive plate. The dye-sensitized solar cell of claim 10, wherein the catalytic layer comprises platinum.