CN102347138A - Electrolyte composition for dye-sensitized solar cell and solar cell using same - Google Patents

Abstract

An electrolyte composition for a dye-sensitized solar cell includes an organic amine hydroiodide; an imidazole salt; iodine; guanidine thiocyanate; a benzimidazole derivative, a pyridine derivative or a mixture thereof; and a solvent. The present invention provides a dye-sensitized solar cell, including a photoanode; a cathode; and a layer formed by the electrolyte composition of the present invention, formed on the surface where the cathode contacts the photoanode. The dye-sensitized solar cell prepared using the electrolyte composition of the present invention has excellent photoelectric conversion performance, and the components of the electrolyte composition are highly compatible, and have the advantages of not being easy to dry up and providing stable photoelectric conversion efficiency.

Description

Electrolyte composition for dye-sensitized solar cell and solar cell using same

technical field

The invention relates to an electrolyte composition, in particular to an electrolyte composition suitable for a dye-sensitized solar cell (Dye-Sensitized Solar Cell, DSC). The present invention also relates to a dye-sensitized solar cell using the electrolyte composition.

Background technique

With the development of human civilization, the world is facing serious problems such as energy crisis and environmental pollution. Among them, solar cells, which can directly convert solar energy into electrical energy, are one of the important methods to solve the world's energy crisis and reduce environmental pollution. In solar cells, dye-sensitized solar cells have gradually become a promising new type due to their low manufacturing cost, large area, flexibility, and light transmission, which can be used in buildings. Solar battery.

等人发表一系列染料敏化太阳能电池相关文献(例如O’Regan，B.；

M.Nature 1991，353，737)，显示染料敏化太阳能电池具有实用性。一般而言，染料敏化太阳能电池的结构包括阴/阳电极、纳米二氧化钛、染料及电解质，其中，电解质对电池效率有关键性的影响。在染料敏化太阳能电池中，理想的电解质必须具备不易挥发、不易泄漏、易封装、不易破坏染料及其他成份等特性。in recent years,

et al published a series of literature on dye-sensitized solar cells (such as O'Regan, B.;

M. Nature 1991, 353, 737), showing the practicality of dye-sensitized solar cells. Generally speaking, the structure of dye-sensitized solar cells includes cathode/anode electrodes, nano-titanium dioxide, dyes, and electrolytes, among which electrolytes have a key impact on cell efficiency. In dye-sensitized solar cells, the ideal electrolyte must have the characteristics of low volatility, low leakage, easy packaging, and low damage to dyes and other components.

Liquid electrolyte is currently known to have a high photoelectric conversion efficiency. Generally speaking, it has disadvantages such as volatile, easy to leak, and difficult to package. In order to solve the above problems, people have tried many methods, such as ionic liquid (N.Papageorgiou et al., J.Electrochem.Soc, 1996,143,3099); colloidal electrolyte (U.S.Pat. .No.6245847).

The electrolyte in dye-sensitized solar cells has a critical impact on cell efficiency. Therefore, how to improve the efficiency of dye-sensitized solar cells through electrolytes has become an urgent issue for the solar cell industry to solve.

Contents of the invention

In view of this, the present invention provides a dye-sensitized solar cell electrolyte composition, comprising:

(a) organic amine hydroiodide, the weight percentage is 2 to 25%;

(b) imidazolium salt, the weight percentage is 2 to 25%;

(c) iodine, 0.5 to 5% by weight;

(d) Guanidine thiocyanate (GuNCS), percentage by weight is 1 to 5%;

(e) benzimidazole derivatives, pyridine derivatives or mixtures thereof in a weight percentage of 2 to 15%; and

(f) Solvent, 50 to 92.5% by weight.

Preferably, the weight percentage of component (a) is 5 to 20%; the weight percentage of component (b) is 2 to 20%; the weight percentage of component (c) is 0.5 to 3%; component (d) The weight percentage of component (e) is 1 to 3%; the weight percentage of component (e) is 5 to 10%; and the weight percentage of component (f) is 60 to 86.5%. Most preferably, the weight percentage of component (a) is 15.1%; The weight percentage of component (b) is 2.3%; The weight percentage of component (c) is 1.3%; The weight percentage of component (d) is 1.2% %; 8.7% by weight of component (e); and 71.4% by weight of component (f).

In a specific embodiment, (a) organic amine hydroiodide can be triethylamine hydroiodide (Triethylaminehydroiodide, THI), tripropylamine hydroiodide (Tripropylamine hydriodide), tributylamine hydroiodide (Tributylamine hydriodide), Tripentylamine hydriodide, Trihexylamine hydriodide or a mixture thereof, specifically, the mixture refers to that the electrolyte composition of the present invention may include two or more of the aforementioned organic amine hydriodides . In addition, the preferred (a) organic amine hydriodate is triethylamine hydriodate, tripropylamine hydriodate, or tributylamine hydriodate, or a mixture thereof. The most preferred organic amine hydriodide is triethylamine hydriodide.

The above-mentioned component (b) imidazolium salt can be 1-methyl-3-propylimidazolium iodide (1-Methyl-3-propylimidazolium iodide, PMII), 1,3-dimethyl imidazolium iodide (1, 3-Dimethylimidazolium iodide), 1-Methyl-3-ethylimidazolium iodide (1-Methyl-3-ethylimidazolium iodide), 1-Methyl-3-butyl imidazolium iodide (1-Methyl-3- butylimidazolium iodide), 1-methyl-3-pentyl imidazolium iodide (1-Methyl-3-pentyl-imidazolium iodide), 1-methyl-3-hexyl imidazolium iodide (1-Methyl-3-hexylimidazolium iodide), 1-Methyl-3-heptylimidazolium iodide, 1-Methyl-3-octylimidazolium iodide , 1,3-diethylimidazolium iodide (1,3-Diethylimidazolium iodide), 1-ethyl-3-propyl imidazolium iodide (1-Ethyl-3-propylimidazolium iodide), 1-ethyl- 3-butyl imidazolium iodide (1-Ethyl-3-butylimidazolium iodide), 1,3-dipropylimidazolium iodide (1,3-dipropylimidazolium iodide), 1-propyl-3-butyl iodide Imidazolium (1-Propyl-3-butylimidazolium iodide) or a mixture thereof. And with 1-methyl-3-propyl imidazolium iodide, 1-methyl-3-ethyl imidazolium iodide, 1-methyl-3-butyl imidazolium iodide, 1-methyl-3 -Pentyl imidazolium iodide, 1-methyl-3-hexyl imidazolium iodide, 1,3-diethyl imidazolium iodide, 1-ethyl-3-propyl imidazolium iodide, 1-ethyl Base-3-butyl imidazolium iodide, 1,3-dipropyl imidazolium iodide, 1-propyl-3-butyl imidazolium iodide or their mixtures are preferred; more preferred imidazolium salt is 1 -Methyl-3-propylimidazolium iodide, 1-methyl-3-ethylimidazolium iodide, 1-methyl-3-butylimidazolium iodide, 1-methyl-3-pentyl Imidazolium iodide, 1-methyl-3-hexyl imidazolium iodide, 1,3-diethylimidazolium iodide, 1-ethyl-3-propyl imidazolium iodide, 1-ethyl-3 -Butylimidazolium iodide or mixtures thereof; most preferably, it may be selected from 1-methyl-3-propylimidazolium iodide, 1-methyl-3-ethylimidazolium iodide, 1-methylimidazolium iodide, Base-3-butyl imidazolium iodide, 1-methyl-3-pentyl imidazolium iodide, 1,3-diethyl imidazolium iodide, 1-ethyl-3-propyl imidazolium iodide or a mixture thereof.

In a specific embodiment of the present invention, (e) benzimidazole derivatives, pyridine derivatives or mixtures thereof may be N-methylbenzimidazole (N-Methylbenzimidazole, NMBI), N-butylbenzimidazole (N - Butylbenzimidazole, NBB), tert-butylpyridine (4-tert-Butylpyridine, 4-TBP) or a mixture thereof.

In a specific embodiment of the present invention, the solvent used includes acetonitrile (Acetonitrile, ACN), 3-methoxyl-propionitrile (3-MPN), N-methylpyrrolidone (N -Methyl-2-pyrrolidone (NMP), gamma-butyrolactone (GBL), propylene carbonate (PC), ethylene carbonate (EC) or mixtures thereof. On the other hand, the present invention also provides a dye-sensitized solar cell containing the electrolyte composition of the present invention. The dye-sensitized solar cell of the present invention comprises: a photoanode (photoanode) containing a dye compound; a cathode (cathode); and an electrolyte layer (electrolyte layer) between the photoanode and the cathode using the electrolyte composition of the present invention. Specifically, the electrolyte layer is formed on the surface of the cathode in contact with the photoanode.

In the dye-sensitized solar cell of the present invention, the photoanode includes: a substrate, a porous semiconductor film, a conductive film formed between the substrate and the porous semiconductor film, and a dye compound disposed on the conductive film and filled in the In the pores of the porous semiconductor film, and the electrolyte layer is formed between the cathode and the porous semiconductor film. In practical applications, a transparent substrate and a transparent conductive film are generally used, and the material of the transparent substrate is not particularly limited, as long as it is a transparent substrate, it can be used. Preferably, the material of the transparent substrate is a transparent substrate with good barrier properties, solvent resistance, weather resistance, etc. for moisture or gas intruding from the outside of the dye-sensitized solar cell. Non-limiting examples of transparent substrates include: substrates made of transparent inorganic materials such as quartz and glass; polyethylene terephthalate (PET), poly(ethylene naphthalate) (PEN), polycarbonate (PC), polyethylene (PE), polypropylene (PP), polyimide (PI) and other transparent plastic substrates. In addition, the thickness of the transparent substrate is not particularly limited, and can be freely selected according to the light transmittance and the characteristic requirements of the dye-sensitized solar cell. Preferably, the material of the transparent substrate is glass.

In addition, in the dye-sensitized solar cell of the present invention, the material of the conductive film may be indium tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide-gallium trioxide (znO-Ga ₂ O ₃ ), Zinc oxide-aluminum oxide (ZnO-Al ₂ O ₃ ), or tin-based oxide materials.

Furthermore, in the dye-sensitized solar cell of the present invention, the porous semiconductor film can be formed using semiconductor fine particles. Suitable semiconductor particles may include silicon, titanium dioxide, tin dioxide, zinc oxide, tungsten trioxide, niobium pentoxide, strontium titanium trioxide, and combinations thereof. A preferred semiconductor fine particle is titanium dioxide. Usually, the average particle diameter of the semiconductor fine particles is 5 to 500 nm, preferably 10 to 50 nm. The thickness of the porous semiconductor film is 5 to 25 micrometers.

In addition, the material for the cathode of the dye-sensitized solar cell is not particularly limited, and may include any conductive material. Alternatively, the cathode material can also be an insulating substrate, as long as a conductive layer is formed on the surface of the substrate facing the photoanode. Typically, an electrochemically stable substance is sufficient for the cathode, and non-limiting examples of suitable cathode materials include platinum, gold, carbon, and the like.

The invention provides a novel electrolyte composition suitable for dye-sensitized solar cells. Due to the excellent photoelectric conversion efficiency and long-term stability of the electrolyte composition of the present invention, the dye-sensitized solar cell produced by using the electrolyte composition of the present invention has excellent photoelectric properties.

Detailed ways

The implementation of the present invention is described below through specific specific examples, and those of ordinary skill in the art can easily understand the efficacy and characteristics of the present invention from the content disclosed in this specification.

In order to obtain the electrolyte composition for dye-sensitized solar cells of the present invention, after mixing organic amine hydroiodide (such as THI, TEAI... etc.) and imidazolium iodide (such as PMII, EMII... etc.), add benzene and imidazole compound and guanidine thiocyanate, and then prepare an electrolyte liquid with a proper concentration with a solvent.

The method for producing the dye-sensitized solar cell of the present invention is not particularly limited, and generally known methods can be used. The porous semiconductor film used in the present invention is made of only semiconductor fine particles. Suitable semiconductor particles include silicon, titanium dioxide, tin dioxide, zinc oxide, tungsten trioxide, niobium pentoxide, strontium titanium trioxide, and combinations thereof. Therefore, in the production of the photoanode, the semiconductor particles are first formulated into a paste, and then coated on the transparent conductive substrate. The coating method can be squeegee, screen printing, spin coating, spraying, etc. or general wet method coating. In addition, in order to obtain an appropriate film thickness, it may be applied one or more times. The semiconductor film layer can be single-layer or multi-layer, and multi-layer refers to the use of semiconductor particles with different particle sizes in each layer. For example, semiconductor particles with a diameter of 5 to 50 nm can be coated at a thickness of 5 to 20 microns, and then semiconductor particles with a particle size of 200 to 400 nm can be coated at a thickness of 3 to 5 microns. Then, after drying at 50-100° C., and then sintering at 400-500° C. for about 30 minutes, a multi-layer semiconductor film can be obtained.

As for the dye compound disposed on the conductive film and filled in the pores of the porous semiconductor film, for example, N-719 dye can be dissolved in an appropriate solvent to prepare a dye solution. Suitable solvents include, but are not limited to, acetonitrile, methanol, ethanol, propanol, butanol, dimethylformamide, N-methylpyrrolidone, or mixtures thereof. Next, the transparent substrate coated with the porous semiconductor film is soaked in the dye solution, the porous semiconductor film is allowed to fully absorb the dye in the dye solution, and after drying, the photoanode of the dye-sensitized solar cell can be prepared.

A specific manufacturing method of the dye-sensitized solar cell of the present invention is as follows. First, the paste comprising titanium oxide particles with a particle size of 20 to 30 nanometers is screen-printed once or several times on a glass plate covered with fluorine-doped tin oxide (FTO), and then Sinter at 450°C for 30 minutes.

The dye compound was dissolved in a mixture of acetonitrile (ACN) and t-butanol at a volume ratio of 1:1 to form a dye solution. Next, soak the above-mentioned glass plate containing the porous titanium oxide film in the dye solution to absorb the dye in the dye solution, take it out and dry it to obtain a photoanode.

In addition, take a tin oxide glass covered with fluorine doping, and drill an injection hole with a diameter of 0.75 mm on the tin oxide glass plate for the purpose of injecting electrolyte. Next, a chloroplatinic acid (H ₂ PtCl ₆ ) solution is coated on the surface of the fluorine-doped tin oxide glass plate, and then heated to 400° C. for about 15 minutes to obtain a cathode.

Then, a thermoplastic polymer film with a thickness of 60 micrometers was placed between the photoanode and the cathode, and surrounded an annular area for containing the electrolyte. Apply pressure to the two electrodes at 120 to 140° C. to bond the two electrodes.

The electrolyte of the present invention is injected through the injection port, and then the injection port is sealed with a thermoplastic polymer film to obtain the dye-sensitized solar cell of the present invention.

The characteristics and functions of the present invention are further described below through specific specific examples, but they are not intended to limit the scope of the present invention.

The photoelectric efficiency test of embodiment 1 to 3 and comparative example 1

The electrolyte composition is formulated according to the ingredients listed in the following table 1, and dye-sensitized solar cells are prepared using N719 dyes, wherein the difference between the comparative examples and the examples is that the comparative examples do not use triethylamine hydroiodate (THI) . For the photoelectric efficiency test, the short circuit current (J _SC ), open circuit voltage (V _OC ), photoelectric conversion efficiency (η) and fill factor (FF) of the battery are recorded in Table 2.

Table 1

Table 2

serial number Voc(V) Jsc(mA/cm ² ) FF η(%) Comparative example 1 0.72 9.84 61.2 4.35 Example 1 0.73 11.43 60.0 5.00 Example 2 0.77 10.60 61.3 5.02 Example 3 0.76 10.68 58.3 4.71

Examples 1 to 3 use different solvents to prepare electrolyte compositions and perform element efficiency tests, wherein the solvents include 3-methoxypropionitrile (MPN), γ-butyrolactone (GBL), and propylene carbonate (PC) respectively. , Ethylene carbonate (EC). As shown in the table, the current and voltage values of the dye-sensitized solar cell made according to the composition of the embodiment are all higher than the values measured in Comparative Example 1 that do not contain triethylamine hydriodate (THI) in the electrolyte. Similarly, using The dye-sensitized solar cell efficiency of the electrolyte composition of the present invention is also higher.

The photoelectric efficiency test of embodiment 4 to 8 and comparative example 2

The electrolyte composition was formulated according to the ingredients listed in Table 3 below, and a dye-sensitized solar cell was prepared using N719 dye, wherein the difference between the comparative example and the example was that the comparative example did not use 1-methyl-3-propyl imidazolium iodide (PMII). For the photoelectric efficiency test, the short circuit current (J _SC ), open circuit voltage (V _OC ), photoelectric conversion efficiency (η) and fill factor (FF) of the battery are recorded in Table 4.

table 3

Table 4

serial number Voc(V) Jsc(mA/cm ² ) FF η(%) Comparative example 2 0.74 8.58 64.7 4.09 Example 4 0.74 8.92 62.3 4.09 Example 5 0.75 9.10 61.1 4.16 Example 6 0.76 9.19 62.4 4.35 Example 7 0.766 9.82 59.15 4.45 Example 8 0.76 10.11 59.29 4.56

As shown in Table 4, the dye-sensitized solar cell prepared with the electrolyte composition containing 1-methyl-3-propylimidazolium iodide (PMII) has a higher current value and higher efficiency, and in addition , the use of a solvent with a higher boiling point is also beneficial to the photoelectric conversion efficiency and the increase of the voltage value. Also, preferably, the concentration ratio of the N,N-substituted imidazolium salt to the hydroiodide salt of the organic amine is 1.1 to 5. In addition, in the preferred embodiment, a very good photoelectric conversion efficiency can also be obtained by using a mixed solvent as in Examples 3, 7 and 8, and in a specific embodiment, the volume ratio of propylene carbonate to ethylene carbonate is 1:1.

The photoelectric efficiency test of embodiment 1 and 2 and comparative example 3

The electrolyte composition of Comparative Example 3 shown in Table 5 is a known electrolyte containing inorganic metal salts, and Table 6 shows the measured short-circuit current (J _SC ), open circuit Voltage (V _OC ), photoelectric conversion efficiency (η) and fill factor (FF).

table 5

Table 6

serial number Voc(V) Jsc(mA/cm ² ) FF η(%) Comparative example 3 0.73 11.38 60.4 5.02 Example 1 0.73 11.43 60.0 5.00 Example 2 0.77 10.60 61.3 5.02

As can be seen from the data shown in Table 6, the novel electrolyte composition proposed by the present invention has properties equivalent to known electrolytes containing inorganic salts. Since the electrolyte composition of the present invention does not contain inorganic metals, the compatibility between the components is better. The configuration of various electrolyte concentrations can be realized, which can avoid electrolyte drying and provide stable photoelectric conversion efficiency.

Invention effect

Among the various chemicals in dye-sensitized solar cells, the electrolyte is a substance that provides redox, and the efficiency and stability of dye-sensitized solar cell components and modules depend on the composition of the electrolyte. Therefore, if the electrolyte formulation can be matched The components that can increase the current and voltage and the solvent with a high boiling point can become an electrolyte with high chemical stability. The present invention uses metal iodide salts (such as LiI, NaI, KI...etc.) that are different from general commonly used, and uses organic amine hydroiodide (such as THI, TEAI...etc.), collocation imidazolium iodide (such as PMII , EMII... etc.), and add N-butylbenzimidazole (or N-methylbenzimidazole or tert-butylpyridine) and guanidine thiocyanate, and then match it with a high boiling point solvent to make it a chemically stable Electrolyte components to achieve high photoelectric conversion efficiency and long-term stability.

To sum up, the present invention shows characteristics that are quite different from the known technologies in terms of purpose, method and effect, or in terms of its technical level and R&D design. It should be noted that the above-mentioned embodiments are described as examples for the convenience of illustration only, but they are not intended to limit the present invention. Any person skilled in the art may make some changes or modifications without departing from the spirit and scope of the present invention. Therefore, the scope of rights claimed by the present invention should be based on the claims, rather than limited to the above-mentioned embodiments.

Claims (16)

1. electrolyte for dye-sensitized solar cell composition comprises:

(a) organic amine hydriodate, percentage by weight are 2 to 25%;

(b) imidazole salts, percentage by weight are 2 to 25%;

(c) iodine, percentage by weight are 0.5 to 5%;

(d) guanidine thiocyanate, percentage by weight are 1 to 5%;

(e) benzimidizole derivatives, pyridine derivate or its mixture, percentage by weight is 2～15%; And

(f) solvent, percentage by weight are 50 to 92.5%.

2. electrolyte composition as claimed in claim 1, wherein, said (a) organic amine hydriodate is selected from hydroiodic acid triethylamine, hydroiodic acid tripropyl amine (TPA), hydroiodic acid tri-n-butylamine, hydroiodic acid triamylamine, hydroiodic acid trihexylamine or its mixture.

3. according to claim 1 or claim 2 electrolyte composition; Wherein, Said (b) imidazole salts is selected from 1-methyl-3-propyl group iodate imidazoles, 1; 3-dimethyl iodate imidazoles, 1-methyl-3-ethyl iodate imidazoles, 1-methyl-3-butyl iodate imidazoles, 1-methyl-3-amyl group iodate imidazoles, 1-methyl-3-hexyl iodate imidazoles, 1-methyl-3-heptyl iodate imidazoles, 1-methyl-3-octyl group iodate imidazoles, 1; 3-diethyl iodate imidazoles, 1-ethyl-3-propyl group iodate imidazoles, 1-ethyl-3-butyl iodate imidazoles, 1,3-dipropyl iodate imidazoles, 1-propyl group-3-butyl iodate imidazoles or its mixture.

4. according to claim 1 or claim 2 electrolyte composition, wherein, said (e) benzimidizole derivatives, pyridine derivate or its mixture are selected from N-tolimidazole, N-butyl benzimidazole, tert .-butylpyridine or its mixture.

5. according to claim 1 or claim 2 electrolyte composition, wherein, said (f) solvent is selected from acetonitrile, 3-methoxypropionitrile, N-methyl arsenic noise made in coughing or vomiting alkane ketone, gamma-butyrolacton, propene carbonate, ethylene carbonate or its mixture.

6. electrolyte composition as claimed in claim 3, wherein, said (e) benzimidizole derivatives, pyridine derivate or its mixture are selected from N-tolimidazole, N-butyl benzimidazole, tert .-butylpyridine or its mixture.

7. electrolyte composition as claimed in claim 6, wherein, said (f) solvent is selected from acetonitrile, 3-methoxypropionitrile, N-methyl arsenic noise made in coughing or vomiting alkane ketone, gamma-butyrolacton, propene carbonate, ethylene carbonate or its mixture.

8. electrolyte composition as claimed in claim 1, wherein, the percentage by weight of said organic amine hydriodate is 15.1%; The percentage by weight of imidazole salts is 2.3%; The percentage by weight of iodine is 1.3%; The percentage by weight of guanidine thiocyanate is 1.2%; Be somebody's turn to do the percentage by weight 8.7% of (e) benzimidizole derivatives, pyridine derivate or its mixture; And be somebody's turn to do the percentage by weight 71.4% of (f) solvent.

9. DSSC comprises:

(A) photo cathode;

(B) negative electrode; And

(C) dielectric substrate is formed on this negative electrode and the surface that this photo cathode contacts, and said dielectric substrate comprises

(a) organic amine hydriodate;

(b) imidazole salts;

(c) iodine;

(d) guanidine thiocyanate;

(e) benzimidizole derivatives, pyridine derivate or its mixture; And

(f) solvent.

10. DSSC as claimed in claim 9; Wherein, Said photo cathode comprises substrate, porous semiconductor film, is formed at conducting film and dye composition between this substrate and the porous semiconductor film, and said dye composition is arranged on the conducting film and is filled in the hole of porous semiconductor film.

11. DSSC as claimed in claim 10, wherein, said dielectric substrate is formed between said negative electrode and the porous semiconductor film.

12. DSSC as claimed in claim 9, wherein, said (a) organic amine hydriodate is selected from hydroiodic acid triethylamine, hydroiodic acid tripropyl amine (TPA), hydroiodic acid tri-n-butylamine, hydroiodic acid triamylamine, hydroiodic acid trihexylamine or its mixture.

13. DSSC as claimed in claim 9; Wherein, Said (b) imidazole salts is selected from 1-methyl-3-propyl group iodate imidazoles, 1; 3-dimethyl iodate imidazoles, 1-methyl-3-ethyl iodate imidazoles, 1-methyl-3-butyl iodate imidazoles, 1-methyl-3-amyl group iodate imidazoles, 1-methyl-3-hexyl iodate imidazoles, 1-methyl-3-heptyl iodate imidazoles, 1-methyl-3-octyl group iodate imidazoles, 1; 3-diethyl iodate imidazoles, 1-ethyl-3-propyl group iodate imidazoles, 1-ethyl-3-butyl iodate imidazoles, 1,3-dipropyl iodate imidazoles, 1-propyl group-3-butyl iodate imidazoles or its mixture.

14. DSSC as claimed in claim 9, wherein, said (e) benzimidizole derivatives, pyridine derivate or its mixture are selected from N-tolimidazole, N-butyl benzimidazole, tert .-butylpyridine or its mixture.

15. DSSC as claimed in claim 9, wherein, said (f) solvent is selected from acetonitrile, 3-methoxypropionitrile, N-methyl arsenic noise made in coughing or vomiting alkane ketone, gamma-butyrolacton, propene carbonate, ethylene carbonate or its mixture.

16. DSSC as claimed in claim 12; Wherein, Said (b) imidazole salts is selected from 1-methyl-3-propyl group iodate imidazoles, 1; 3-dimethyl iodate imidazoles, 1-methyl-3-ethyl iodate imidazoles, 1-methyl-3-butyl iodate imidazoles, 1-methyl-3-amyl group iodate imidazoles, 1-methyl-3-hexyl iodate imidazoles, 1-methyl-3-heptyl iodate imidazoles, 1-methyl-3-octyl group iodate imidazoles, 1; 3-diethyl iodate imidazoles, 1-ethyl-3-propyl group iodate imidazoles, 1-ethyl-3-butyl iodate imidazoles, 1,3-dipropyl iodate imidazoles, 1-propyl group-3-butyl iodate imidazoles or its mixture; Said (e) benzimidizole derivatives, pyridine derivate or its mixture are selected from N-tolimidazole, N-butyl benzimidazole, tert .-butylpyridine or its mixture; And said (f) solvent is selected from acetonitrile, 3-methoxypropionitrile, N-methyl arsenic noise made in coughing or vomiting alkane ketone, gamma-butyrolacton, propene carbonate, ethylene carbonate or its mixture.