CN104377036B - Method for preparing AgInS2 quantum dot sensitized TiO2 photoelectrode with In2S3 used as buffer layer - Google Patents

Abstract

The invention relates to a method for preparing an AgInS2 quantum dot sensitized TiO2 photoelectrode with In2S3 used as a buffer layer. The method comprises the steps that (1) a TiO2 porous membrane is prepared on an FTO conducting glass matrix; (2) an Ag2S quantum dot sensitized TiO2 electrode is obtained through the continuous ionic adsorption reaction method; (3) on the Ag2S quantum dot/TiO2 electrode, the chemical bath deposition and reaction of In2S3 is used for synthesizing the AgInS2 quantum dot sensitized TiO2 photoelectrode with In2S3 used as the buffer layer in a one-step in-situ mode. The method is simple in preparing process and low in requirement for equipment, and common organic solvents used for semiconductor quantum dot synthesis are not involved; the photoelectrode is composed of AgInS2, In2S3 and TiO2 which are low in toxicity, has high photoelectric response performance when being applied to solar cells, and has potential application prospects.

Description

A kind of In2S3AgInS for cushion2Quantum dot sensitized TiO2The preparation of optoelectronic pole Method

Technical field

The invention belongs to quantum dot sensitized TiO₂Optoelectronic pole field, particularly to a kind of In₂S₃AgInS for cushion₂ Quantum dot sensitized TiO₂The preparation method of optoelectronic pole.

Background technology

Research to semiconductor-quantum-point has been enter into unprecedented fieriness at present, and it even more currently gathers in the application of photoelectric field Burnt center.However, obtaining the quantum dot (QDs) used by main research progress at present is the element such as Cd, Pb, it is currently right not meet Environmental protection, the strategic requirement of environmentally friendly material, thus limit its application in various fields.Novel tertiary I-II-VI race Semiconductor-quantum-point not only possesses the excellent properties that quantum dot has, and simultaneously with the advantage of its low toxic and environment-friendly, is expected to replace The application in each field for the Cd system quantum dot.AgInS₂Semiconductor is the ternary chalcogenide thing of direct band gap, forms four during low temperature The yellow copper structure of square phase, band gap be 1.87eV, during high temperature formed orthorhombic phase structure, its band gap about 2.03eV, body material swash Sub- Bohr radius is about 5.5nm；It has good stability, has higher absorption coefficient and hypotoxicity, in biology to heat and electricity Huge application prospect is shown in fluorescence labeling, LED, nonlinear device, visible light catalytic and area of solar cell.

Solar energy is to be hopeful one of energy of being used widely in 21 century most, its using in, solar cell is sent out Electricity attracts most attention, and it has, and conversion link is few, the resource amount of containing is inexhaustible, energy quality is high, the construction period is short, generation mode Close to advantages such as zero-emissions.With nano-TiO₂Material has drawn as dye-sensitized solar cells (DSSCs) research of optoelectronic pole Play the extensive concern of people, be generally considered second generation solar cell, it will gradually replaced traditional solar cell, become Emphasis for the development of solar cell from now on.But some factors such as cost of dye is higher, dyestuff easily occurs light degradation to lead to imitate Rate reduces, the absorption spectrum of dyestuff is narrower, dyestuff multilayer adsorbs the development that the problems such as be unfavorable for electric transmission constrains DSSCs. Therefore, find a kind of new photosensitive materials and replace dyestuff, the development to solar cell has important meaning.Narrow band gap Inorganic semiconductor material can replace dyestuff as sensitizer, if by these controls of material in the range of quantum effect, the amount of becoming Son point sensitizer.

The quantum dot sensitized TiO of I-II-VI race₂The preparation of optoelectronic pole is based primarily upon two methods：One is pre-synthesis quantum Point, disperses in the solution, by nanoporous TiO after purification₂Quantum dot is adsorbed in film immersion solution.Synthesize by this method Quantum dot size is uniform, purity is high, but because quantum dot passes through physisorption and TiO₂Film combination, the stability of battery Poor；It is related to more organic solvent in quantum dot building-up process, not only causes environmental pollution, so that preparation cost is increased；Two are In TiO₂" in situ " quantum dot sensitized optoelectronic pole is synthesized, as high-temperature spray pyrolysismethod, high temperature vulcanized method electrochemistry are sunk on film Area method, vapour deposition process etc., the harsh and prepared quantum dot purity of such method preparation condition is relatively low.I-II-VI race quantum dot And TiO₂Lattice mismatches, in order to improve quantum dot and TiO₂Interracial contact, conventional In₂S₃、Cu₂S、In₂Se₃In work For interface cushion, so as to suppressing electronics recombination rate, improving battery performance.In₂S₃Cushion is mostly in pre-synthesis electricity The extremely upper method such as chemical bath deposition, high temperature plated film is obtained, and preparation technology is more complicated, cost is also higher.

Content of the invention

The invention provides a kind of In₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation method of optoelectronic pole, should Method preparation process is simple, the requirement to equipment is relatively low, be not related to the conventional organic solvent of semiconductor-quantum-point synthesis；Optoelectronic pole By the relatively low AgInS of toxicity₂、In₂S₃And TiO₂Constitute, application has stronger photoelectric response performance in solar cells, has latent Application prospect.

A kind of In of the present invention₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation method of optoelectronic pole, including：

(1) by TiO₂Nano-powder roasting, obtains pretreated TiO₂Nano-powder；TiO after the pre-treatment₂Nanometer In powder, add water, absolute ethyl alcohol, acetic acid and binding agent, ball milling (6～36h), (30 DEG C～80 DEG C) vacuum distillation concentrates, and obtains Obtain TiO₂Viscous paste；Then it is coated on FTO electro-conductive glass matrix, roasting, obtain TiO on glass basis₂Perforated membrane；

(2) by TiO₂Perforated membrane is immersed in Ag⁺In the aqueous solution, after deionized water, ethanol washing, put into S^2-In the aqueous solution Impregnation, then the washing of deionized water, ethanol, obtain after continuous ion adsorbing method SILAR circulation (2～14 times) Ag₂S-QDs is sensitized TiO₂Electrode；

(3) by containing indium salts, sulphur source, complexing agent In₂S₃Presoma homogeneous phase aqueous solution is added in water heating kettle, by Ag₂S- QDs is sensitized TiO₂Electrode is placed in solution, is heated to 80～200 DEG C after sealing, and hydro-thermal 2～10h spends after being cooled to room temperature Ionized water, absolute ethanol washing, naturally dry and obtain In₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂Optoelectronic pole.

TiO in described step (1)₂The particle diameter of nano-powder is 20～50 nanometers, and crystal formation is anatase titanium dioxide or rutile-type One of or two kinds.

Binding agent in described step (1) is polyethylene glycol, polyvinyl pyrrole, polyvinyl alcohol, in poly- ethyl cellulose One or more, binding agent and TiO₂The mass ratio of powder is 0.5:1～10:1.

Coating method in described step (1) is serigraphy or knife coating；Coating layer thickness is 4 μm～20 μm, and coating is big Little is 0.5～6cm².

TiO in described step (1)₂Nano-powder be roasted to roasting 1～10h at 200 DEG C～600 DEG C；TiO₂Sticky Slurry be roasted to roasting 1～6h at 200 DEG C～500 DEG C.

Ag in described step (2)⁺Selected from one or more of silver nitrate, silver sulfate, silver acetate, S^2-For vulcanized sodium, sulphur One of sodium hydride or two kinds.

Ag in described step (2)⁺The molar concentration of the aqueous solution is 0.001～0.5mol/L, S^2-The molar concentration of the aqueous solution For 0.001～0.5mol/L.

In Ag in described step (2)⁺The aqueous solution or S^2-The dip time of the aqueous solution is 10～120s.

Indium salts in described step (3) are selected from one or more of indium nitrate, indium sulfate, indium acetate；Sulphur source is selected from sulphur For one or more of acetyl, thiocarbamide, vulcanized sodium, mercaptopropionic acid；Complexing agent is selected from polyvinylpyrrolidone, ethylenediamine tetrem One or more of acid, citric acid, nitrilotriacetic acid.

In in described step (3)₂S₃In presoma homogeneous phase aqueous solution, the molar concentration of indium salts is 0.001～0.1mol/L, The molar concentration of sulphur source is 0.004～0.4mol/L, and the molar concentration of complexing agent is 0.004～1.0mol/L.

Beneficial effect

, for process is simple, cost is relatively low, not etching apparatus, especially prepares in aqueous phase system for the present invention, reaction During be not related to the conventional organic solvent of quantum dot synthesis, the requirement of environmental protection can be met；Prepared optoelectronic pole is vulcanized with more The solar cell that thing electrolyte, platinum are dressed up to electrode group, has stronger photoelectric respone under standard analog sunlight conditions Can, there is potential application prospect.

Specific embodiment

With reference to specific embodiment, the present invention is expanded on further.It should be understood that these embodiments are merely to illustrate the present invention Rather than restriction the scope of the present invention.In addition, it is to be understood that after having read the content of present invention instruction, people in the art Member can make various changes or modifications to the present invention, and these equivalent form of values equally fall within the application appended claims and limited Scope.

Embodiment 1

Weigh 2.0g nano-TiO₂Powder (the weight ratio about 80/20 of mixed crystal type, anatase and rutile), puts into horse Not in stove, roasting 3h at 200 DEG C.TiO₂The particle diameter of nano-powder is 25 nanometers.60mL absolute ethyl alcohol add pre- The nano-TiO processing₂Powder, stirring, add 1.0g deionized water, 0.5g acetic acid and the poly- ethyl cellulose of 6.0g.Ball milling 24h Afterwards, remove excessive ethanol with Rotary Evaporators in 50 DEG C of vacuum distillations, obtain TiO₂Viscous paste.By the TiO preparing₂Viscous Thick slurry material knife coating is coated on the glass basis after cleaning, and coating layer thickness is about 10 μm, and coating size is 3cm².Then exist Roasting 1h at 480 DEG C, heating rate is 1 DEG C/min, obtains TiO on glass basis₂Perforated membrane.

Porous TiO₂After electrode is immersed in 30s in the 0.02mol/L silver acetate aqueous solution, deionized water, ethanol washing, then Put into dipping 30s in 0.05mol/L sodium sulfide solution, then the washing of deionized water, ethanol.After 6 SILAR circulations To Ag₂S-QDs/TiO₂Electrode.

0.02mol/L indium acetate, 0.08mol/L thiocarbamide, 0.12mol/L citric acid precursor water solution are added to hydro-thermal In kettle, 6 SILAR are circulated the Ag obtaining₂S-QDs/TiO₂Electrode is placed in solution, is heated to 150 DEG C, hydro-thermal after sealing 3h, is cooled to deionized water, absolute ethanol washing after room temperature, naturally dries and obtain In₂S₃AgInS for cushion₂Quantum dot Sensitization TiO₂Optoelectronic pole.

The solar cell that prepared optoelectronic pole is dressed up to electrode group with polysulfide electrolyte, platinum, in standard analog Under sunlight conditions, photoelectric transformation efficiency and density of photocurrent are respectively 0.70%, 7.87mA/cm².

Embodiment 2

Weigh 2.0g nano-TiO₂Powder (the weight ratio about 80/20 of mixed crystal type, anatase and rutile), puts into horse Not in stove, roasting 3h at 200 DEG C.TiO₂The particle diameter of nano-powder is 25 nanometers.60mL absolute ethyl alcohol add pre- The nano-TiO processing₂Powder, stirring, add 1.0g deionized water, 0.5g acetic acid and the poly- ethyl cellulose of 6.0g.Ball milling 24h Afterwards, remove excessive ethanol with Rotary Evaporators in 50 DEG C of vacuum distillations, obtain TiO₂Viscous paste.By the TiO preparing₂Viscous Thick slurry material knife coating is coated on the glass basis after cleaning, and coating layer thickness is about 8 μm, and coating size is 3cm².Then exist Roasting 1h at 480 DEG C, heating rate is 1 DEG C/min, obtains TiO on glass basis₂Perforated membrane.

Porous TiO₂After electrode is immersed in 30s in 0.02mol/L silver nitrate aqueous solution, deionized water, ethanol washing, then Put into dipping 30s in 0.05mol/L sodium sulfide solution, then the washing of deionized water, ethanol.After 4 SILAR circulations To Ag₂S-QDs/TiO₂Electrode.

The precursor water solution of 0.01mol/L inidum chloride, 0.04mol/L thioacetamide, 0.06mol/L citric acid is added Enter in water heating kettle, the Ag that 4 SILAR circulations are obtained₂S-QDs/TiO₂Electrode is placed in solution, is heated to 150 after sealing DEG C, hydro-thermal 3h, it is cooled to deionized water, absolute ethanol washing after room temperature, naturally dry and obtain In₂S₃For cushion AgInS₂Quantum dot sensitized TiO₂Optoelectronic pole.

The solar cell that prepared optoelectronic pole is dressed up to electrode group with polysulfide electrolyte, platinum, in standard analog Under sunlight conditions, photoelectric transformation efficiency and density of photocurrent are respectively 0.54%, 6.82mA/cm².

The above, the only specific embodiment of the present invention, but protection scope of the present invention is not limited thereto, and any Those familiar with the art the invention discloses technical scope in, change or replacement can be readily occurred in, all should contain Cover within protection scope of the present invention.Therefore, protection scope of the present invention should be defined by scope of the claims.

Claims (10)

1. a kind of In₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation method of optoelectronic pole, including：

(1) by TiO₂Nano-powder roasting, obtains pretreated TiO₂Nano-powder；TiO after the pre-treatment₂Nano-powder In, add water, absolute ethyl alcohol, acetic acid and binding agent, ball milling, vacuum distillation concentrates, obtain TiO₂Viscous paste；Then it is coated in On FTO electro-conductive glass matrix, roasting, obtain TiO on glass basis₂Perforated membrane；

(2) by TiO₂Perforated membrane is immersed in Ag⁺In the aqueous solution, after deionized water, ethanol washing, put into S^2-Impregnate in the aqueous solution Reaction, then the washing of deionized water, ethanol, obtain Ag after SILAR method SILAR circulation₂S-QDs is quick Change TiO₂Electrode；

(3) by containing indium salts, sulphur source, complexing agent In₂S₃Presoma homogeneous phase aqueous solution is added in water heating kettle, by Ag₂S-QDs Sensitization TiO₂Electrode is placed in solution, is heated to 80～200 DEG C after sealing, hydro-thermal 2～10h, spend after being cooled to room temperature from Sub- water, absolute ethanol washing, naturally dry and obtain In₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂Optoelectronic pole.

2. a kind of according to claim 1₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation side of optoelectronic pole Method it is characterised in that：TiO in described (1)₂The particle diameter of nano-powder is 20～50 nanometers.

3. a kind of according to claim 1₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation side of optoelectronic pole Method it is characterised in that：Binding agent in described (1) is polyethylene glycol, polyvinyl pyrrole, polyvinyl alcohol, in poly- ethyl cellulose One or more, binding agent and TiO₂The mass ratio of powder is 0.5:1～10:1.

4. a kind of according to claim 1₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation side of optoelectronic pole Method it is characterised in that：The method that coating in described (1) is adopted is serigraphy or knife coating；Coating layer thickness is 4 μm～20 μm, coating size is 0.5～6cm².

5. a kind of according to claim 1₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation side of optoelectronic pole Method it is characterised in that：TiO in described (1)₂Nano-powder be roasted to roasting 1～10h at 200 DEG C～600 DEG C；TiO₂Viscous Thick slurry material be roasted to roasting 1～6h at 200 DEG C～500 DEG C.

6. a kind of according to claim 1₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation side of optoelectronic pole Method it is characterised in that：Ag in described (2)⁺Selected from one or more of silver nitrate, silver sulfate, silver acetate, S^2-For vulcanized sodium, One of NaHS or two kinds.

7. a kind of according to claim 1₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation side of optoelectronic pole Method it is characterised in that：Ag in described (2)⁺The molar concentration of the aqueous solution is 0.001～0.5mol/L, S^2-The aqueous solution mole dense Spend for 0.001～0.5mol/L.

8. a kind of according to claim 1₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation side of optoelectronic pole Method it is characterised in that：In Ag in described (2)⁺The aqueous solution or S^2-The dip time of the aqueous solution is 10～120s.

9. a kind of according to claim 1₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation side of optoelectronic pole Method it is characterised in that：Indium salts in described (3) are selected from one or more of indium nitrate, indium sulfate, indium acetate；Sulphur source is selected from One or more of thioacetyl, thiocarbamide, vulcanized sodium, mercaptopropionic acid；Complexing agent is selected from polyvinylpyrrolidone, ethylenediamine tetraacetic One or more of acetic acid, citric acid, nitrilotriacetic acid.

10. a kind of according to claim 1₂S₃AgInS for cushion₂Quantum dot sensitized TiO₂The preparation side of optoelectronic pole Method it is characterised in that：In in described (3)₂S₃In presoma homogeneous phase aqueous solution, the molar concentration of indium salts is 0.001～0.1mol/ L, the molar concentration of sulphur source is 0.004～0.4mol/L, and the molar concentration of complexing agent is 0.004～1.0mol/L.