CN102856499B - A kind of SnO 2with the preparation method of P3HT hybrid heterojunctions thin-film solar cells - Google Patents

Abstract

A preparation method of _SnO2 and P3HT hybrid heterojunction thin film solar cell. In this method, sulfur powder, ammonium persulfate and metal tin target are used as raw materials, absolute ethanol, DMF and distilled water are used as solvents, and _SnO2 thin films are prepared on ITO conductive glass substrates through hydrothermal and solvothermal heat treatments. SnS is first synthesized by solvothermal method, and its SnS is used as the precursor for preparing SnO ₂ . The oxidation reaction from Sn ²⁺ to Sn ⁴⁺ is simpler and consumes less energy; the morphology of the synthesized SnS is a sheet-like connection network structure, which can be SnO ₂ Growth provides a template, prepares a uniformly distributed loose structure, increases the specific surface area of the SnO ₂ film, and makes the two have better contact when hybridized with P3HT to form a network interpenetration, so as to improve the photoelectric conversion performance of the device. Then spin-coat P3HT on its surface and anneal at 120°C for 2 hours to obtain a heterojunction film hybridized with SnO ₂ and P3HT. The method has simple steps and does not need to use any surfactant and other chemical additives.

Description

A preparation method of SnO2 and P3HT hybrid heterojunction thin film solar cell

technical field

The invention belongs to the technical field of material chemistry, and in particular relates to a method for preparing a SnO ₂ and P3HT hybrid heterojunction thin film on an ITO conductive glass substrate.

Background technique

The global energy demand is increasing year by year, and the development and utilization of solar energy has become a hot topic in the world. In the development process of solar cells, it can be divided into the first generation of solar cells using single crystal silicon and polycrystalline silicon as materials, and the second generation of solar cells using thin film materials to complete photoelectric conversion. The third-generation solar cells of science and technology, and the fourth-generation solar cells are mainly multi-layer structures. People are constantly looking for new materials and methods, hoping to prepare low-cost and high-efficiency solar cells using simple production processes. Organic thin-film solar cells have received great attention. The solubility of organic matter is used to form a film directly on the surface of the electrode at room temperature and pressure to form an active layer. However, due to the low charge mobility of organic matter itself, its energy conversion efficiency is not ideal so far. Unlike organic substances, most inorganic semiconductor materials have high charge mobility, so people combine the advantages of organic and inorganic substances to prepare organic-inorganic hybrid thin-film solar cells.

The Alivisatos research group of California State University, Berkeley reported a conjugated polymer/inorganic semiconductor nanocrystalline hybrid thin film solar cell prepared by using CdSe semiconductor nanorods as acceptors and blending them with P3HT, with an energy efficiency of 1.7%. The polymer of n-type inorganic semiconductor and p-type semiconductor forms an interpenetrating network, and the inorganic semiconductor material as an electron acceptor has the following advantages: (1) The energy level and band gap of nanoparticles can be adjusted by changing the type and size of nanoparticles , so that it has absorption in the entire visible light range, which can expand the absorption range of the polymer organic layer to the solar spectrum, and improve the matching of the battery response spectrum with solar radiation; (2) Nanomaterials have high electron mobility and are chemically stable sex is better. On this basis, people use other inorganic semiconductor materials (ZnO, ZnS, _TiO2 , etc.) to hybridize with organic matter (P3HT or MEHPPV) to prepare a series of solar cell devices with similar structures, and the efficiency is also increased to 5.06%. This opens a new field for the application of inorganic semiconductor nanocrystals and has attracted extensive attention.

SnO ₂ belongs to a wide bandgap n-type semiconductor material with a direct band gap of 3.6eV. As an environmentally friendly semiconductor material, it has good electron transport properties, simple synthesis process, low cost, low toxicity, and good stability. Long service life and other advantages have high application value in the field of photovoltaic cells. At present, they are mostly used in lithium-ion batteries and dye-sensitized batteries. For the hybridization of SnO ₂ and organic conjugated polymers for thin-film solar cells Reports are rare. In addition, as far as the current similar preparation research is concerned, the preparation of such materials mostly uses metal tin salt as the tin source, and the SnO ₂ nanopowder material is prepared by the water and solvothermal method or the sol-gel method, and then the scraper method or rotary coating technology, etc. to prepare thin films; or plant a layer of seed crystals on the substrate to induce growth to form thin films. However, there are some defects in assembling solar photovoltaic devices and testing photoelectric conversion performance: first, the experimental steps in the preparation process are cumbersome and harsh, and some toxic reactants or solvents will be used, which will endanger health and cause pollution; second, In the process of film formation, it is difficult to control the thickness and distribution uniformity of the film by techniques such as seed crystal induced growth or spin coating; therefore, when compounding with organic polymers, it will directly affect the compounding effect, thereby affecting the photoelectric conversion efficiency . Therefore, for semiconductor materials with important application value, regardless of industrial application or laboratory research, higher requirements are put forward for material preparation technology, that is, using simple technology, cheap raw materials, reducing energy consumption as much as possible, and synthesizing environmentally friendly Pollution-free, high-purity products to meet the preparation requirements of today's resource shortage and energy shortage conditions.

The invention adopts water and solvothermal method under low temperature conditions to realize the preparation of _SnO2 nanometer thin film material, and hybridizes it with P3HT, assembles an organic-inorganic hybrid heterojunction thin film solar cell photovoltaic device, and studies its photoelectric conversion performance. The whole preparation process is simple and convenient to operate, environmentally friendly, low in energy consumption, low in raw material cost and free from any toxic by-products.

Contents of the invention

The problem to be solved by the present invention is to provide a chemical method for directly synthesizing _SnO2 nanometer film material with low-temperature water and solvothermal on the conductive glass substrate, and hybridize it with P3HT to prepare _SnO2 and P3HT ( _SnO2 /P3HT ) hybrid heterojunction thin film solar cell devices.

The technical scheme that the present invention takes to the problem to be solved is:

An inorganic/organic hybrid heterojunction thin film solar cell device of the present invention is an ITO/SnO ₂ :P3HT/Al inorganic/organic hybrid heterojunction thin film solar cell device.

In a kind of inorganic/organic hybrid heterojunction thin-film solar cell device of the present invention , _SnO Nano thin-film material is prepared in situ at low temperature, and the method is to use nano-Sn ⁽⁰⁾ as tin source, is coated with metallic tin The SnO ₂ nanometer thin film material is synthesized on the ITO conductive glass substrate by hydrothermal and solvothermal two-step chemical wet methods, and the thickness of the thin film material is regulated by the reaction temperature and reaction time conditions.

In the heterojunction thin-film solar cell device of a kind of inorganic/organic hybrid of the present invention , _SnO The method for in-situ preparation of nano-thin film material at low temperature is, at first utilize magnetron sputtering to sputter one on ITO conductive glass substrate A layer of metal tin, the ITO conductive glass sheet sputtered with a layer of metal tin is placed obliquely in a 30mL polytetrafluoroethylene reactor with the metal side facing up, add 3mg of sulfur powder, and then add absolute ethanol and DMF 10mL each, placed at 160°C for solvothermal reaction for 4 hours, the reaction product was washed more than 2 times with distilled water and absolute ethanol, and dried to obtain the SnS film for use; then the prepared SnS film was placed on a 30mL polytetrafluoroethylene In the reaction kettle, add 3 mg of ammonium persulfate as an oxidant, use distilled water as a solvent, the volume of distilled water is 1/2 to 2/3 of the volume of the container, and react for 24 hours at a temperature of 140 ° C. The reaction product is mixed with distilled water and absolute ethanol Wash more than 2 times and dry at room temperature to obtain the _SnO2 nano film material.

In an inorganic/organic hybrid heterojunction thin film solar cell device of the present invention, the preparation method of _SnO2 and P3HT hybrid heterojunction thin film solar cell is to first utilize magnetron sputtering to sputter on an ITO conductive glass substrate Sputter a layer of metal tin, put the ITO conductive glass piece sputtered with a layer of metal tin on the oblique side in a 30mL polytetrafluoroethylene reactor with the metal side facing up, add 3mg of sulfur powder, and then add absolute ethanol and DMF each 10mL, placed at 160°C for solvothermal reaction for 4 hours, the reaction product was washed more than 2 times with distilled water and absolute ethanol, and dried to obtain the SnS film for use; then the prepared SnS film was placed on a 30mL polystyrene Add 3mg of ammonium persulfate as an oxidant to a vinyl fluoride reaction kettle, use distilled water as a solvent, the volume of distilled water is 1/2-2/3 of the volume of the container, and react at a temperature of 140°C for 24 hours. The reaction product is mixed with distilled water and no Wash with water and ethanol for more than 2 times, and dry at room temperature to obtain _SnO2 nanometer film;

Then, in a vacuum glove box, the prepared 10 mg/mL P3HT was spin-coated on the surface of the prepared SnO ₂ nano-film by the spin coating method, and annealed at 120°C for 2 hours to obtain the hybrid heterogeneous SnO ₂ and P3HT junction thin film solar cells.

A certain amount of P3HT was weighed and dissolved in chloroform to form a 10 mg/mL solution, heated and stirred at 40 ^o C to fully dissolve it. The composite thin film material is a _SnO2 thin film material with a porous structure prepared by a solvothermal method at low temperature, and a layer of P3HT is spin-coated on its surface by a spin-coating method, and the prepared n-type inorganic semiconductor and p-type semiconducting polymer form an interaction. Heterojunction thin films through the network.

The preparation method of the inorganic/organic hybrid heterojunction thin-film solar cell device of the present invention : first prepare SnO according to the above-mentioned steps ₂ and P3HT hybrid heterojunction thin-film material is put into the high-vacuum ion evaporation apparatus, by A layer of aluminum electrode was evaporated by thermal evaporation (vacuum degree 9.0×10 ^-5 mbar), and an ITO/SnO ₂ :P3HT/Al inorganic/organic hybrid heterojunction thin film solar cell device was assembled.

In the present invention, SnS is firstly synthesized by solvothermal method, which acts as a precursor in the process of preparing SnO ₂ , and the oxidation reaction from Sn ²⁺ to Sn ⁴⁺ is simpler and consumes less energy; in addition, the morphology of the synthesized SnS is sheet The network structure of the shape connection can provide a template for the growth of SnO ₂ , prepare a uniformly distributed loose structure, increase the specific surface area of the SnO ₂ film, and make the two have better contact when interpenetrating with the P3HT hybrid network. In order to improve the photoelectric conversion performance of its device.

The invention adopts low-cost raw materials, sulfur powder, ammonium persulfate, metal tin target, and uses absolute ethanol, DMF (N,N-dimethylformamide) and distilled water as solvents, and undergoes simple hydrothermal and solvent thermal treatments. The SnO ₂ thin film can be prepared on the ITO conductive glass substrate. The method has simple steps and does not need to use any surfactant and other chemical additives. It only needs to add ammonium persulfate and the synthesized precursor thin film SnS into the reactor, take it out after hydrothermal reaction for several hours, and wash it repeatedly with water and ethanol. After drying, a white and transparent _SnO2 film with a uniform distribution and a loose structure can be obtained. Then, the surface was coated with P3HT (poly-3-hexylthiophene conjugated polymer) by spin-coating technology, and annealed at 120°C for 2 hours to obtain a heterojunction film hybridized with SnO ₂ and P3HT.

Advantages of the present invention:

1. The present invention uses distilled water, ethanol, and DMF as the reaction medium, and does not need to use toxic solvents, which belongs to an environment-friendly reaction.

2. The present invention is a low-temperature reaction. The reaction only needs to add the reaction raw materials into the reaction kettle, and the desired product can be obtained at 140 ° C. At the same time, no surfactant is used. The cost of the reaction raw materials is low, and the energy consumption is low. Experimental operation Simple.

3. In the present invention, for the first time, the SnO ₂ and P3HT (SnO ₂ /P3HT) hybrid heterojunction thin film is prepared by hybridizing SnO ₂ nano-semiconductor material and P3HT and applied to assembling solar cell devices.

The present invention has important research significance for the development of synthetic organic-inorganic bulk heterojunction composite materials.

Description of drawings

Fig. 1, the _SnO that embodiment 1 prepares Scanning electron micrograph of thin film material

Fig. 2, the SnO that embodiment ₂ prepares Scanning electron micrograph of thin film material

Fig. 3, the _SnO that embodiment 3 prepares Scanning electron micrograph of thin film material

Figure 4, X-ray diffraction pattern (XRD) of the _SnO2 thin film material prepared in Example 3

It can be seen from the XRD diffraction results that, except for the ITO substrate diffraction peaks marked with ★, the other diffraction peaks are all SnO ₂ diffraction peaks, and the corresponding crystal planes have been marked, and no other impurity peaks appear;

Figure 5. Schematic diagram of the SnO ₂ /P3HT hybrid heterojunction thin film solar cell device prepared in Example 3

In the figure: 1-glass substrate, 2-ITO, 3-SnO ₂ /P3HT, 4-Al, 5-insulating layer;

Figure 6, the IV curve of the SnO ₂ /P3HT hybrid heterojunction thin film solar cell device prepared in Example 3

The open circuit voltage (Voc) of the battery is 0.405V, the photocurrent density (Jsc) is 0.321mA/cm ² , and the fill factor (FF) is 15.52%. The current photoelectric conversion efficiency of the battery is 0.02%.

Detailed ways

The present invention is further illustrated below by way of examples.

Example 1

1. Preparation: Wash the PTFE reactor with a volume of 30mL with tap water, distilled water and absolute ethanol for 1-3 times respectively, and dry it for use; use magnetron sputtering to sputter 100nm thick on the ITO conductive glass substrate Metal Sn is for use.

2. Reaction steps: Add 3 mg of sulfur powder to 30 mL of clean polytetrafluoroethylene, then add 10 mL of absolute ethanol and DMF, stir and mix evenly, and then use clean tweezers to pick up the above-mentioned ITO conductive glass sheet sputtered with metal Sn Put it in a 30mL polytetrafluoroethylene reaction kettle with a tilted side, with the metal side facing up, and react at 160°C for 4 hours. Prepare a SnS film on the substrate and set it aside; add 3 mg of ammonium persulfate as an oxidant to a 30 mL clean polytetrafluoroethylene reactor, add 20 mL of distilled water, stir to dissolve, and then place the prepared SnS film on its polytetrafluoroethylene In an ethylene reactor, react at 120°C for 18 hours , wash the reaction product three times with distilled water and absolute ethanol, and dry at a constant temperature of 60°C to obtain the _SnO2 film product, which is a white transparent film. The microstructure under the scanning electron microscope is a loose structure with uniform distribution of nanoparticles, and the scanning electron micrograph is shown in Figure 1.

Example 2

1. Preparation: Wash the PTFE reactor with a volume of 30mL twice with tap water, distilled water and absolute ethanol in turn, and dry it for use; use magnetron sputtering to sputter 200nm thick metal Sn on the ITO conductive glass substrate. stand-by.

2. Reaction steps: Add 3 mg of sulfur powder to a clean polytetrafluoroethylene reactor with a volume of 30 mL, add 10 mL of absolute ethanol and DMF, stir and mix evenly, and then use clean tweezers to pick up the above-mentioned ITO conductive glass sputtered with metal Sn The sheet is placed on the PTFE reactor with the metal side facing upwards, reacted at 160°C for 4 hours, the product is washed with distilled water and absolute ethanol three times, and dried at a constant temperature of 60°C, that is, on the substrate of the ITO conductive glass sheet The SnS film was prepared on the above; add 3 mg of ammonium persulfate as an oxidant into a clean polytetrafluoroethylene reaction kettle with a volume of 30 mL, add 20 mL of distilled water, stir and dissolve, and then place the prepared SnS film on the inclined side in the polytetrafluoroethylene reaction kettle, React at 120°C for 24 hours , wash the reaction product three times with distilled water and absolute ethanol, and dry at a constant temperature of 60°C to obtain the _SnO2 film. The product is a white transparent film, and the microstructure under the scanning electron microscope is a loose structure with uniform particle size distribution. The scanning electron micrograph is shown in FIG. 2 .

Example 3:

1. Preparation: Wash the PTFE reactor with a volume of 30mL twice with tap water, distilled water and absolute ethanol in turn, and dry it for use; use magnetron sputtering to sputter 200nm thick metal Sn on the ITO conductive glass substrate. stand-by.

2. Reaction steps: Add 3 mg of sulfur powder to a clean polytetrafluoroethylene reactor with a volume of 30 mL, add a certain amount of absolute ethanol and 10 mL of DMF each, stir and mix evenly, and then use clean tweezers to pick up the metal Sn sputtered above. The ITO conductive glass piece is placed in a polytetrafluoroethylene reactor on an inclined side, with the metal side facing up, and reacted at 160°C for 4 hours. Prepare a SnS film on a glass substrate for use; add 3 mg of ammonium persulfate as an oxidant to a 30 mL clean polytetrafluoroethylene reactor, add 20 mL of distilled water, stir to dissolve, and then place the prepared SnS film on its polytetrafluoroethylene In an ethylene reactor, react at 140°C for 24 hours , wash the reaction product three times with distilled water and absolute ethanol, and dry at a constant temperature of 60°C to obtain the SnO ₂ film product. The product is a white transparent film, and the microstructure under the scanning electron microscope is a loose structure with uniform particle size distribution. The scanning electron micrograph is shown in FIG. 3 , and the X-ray diffraction pattern is shown in FIG. 4 .

3. Preparation of SnO ₂ /P3HT hybrid heterojunction thin film solar cell device: Spin the prepared 10 mg/mL poly-3-hexylthiophene conjugated polymer (P3HT) in a vacuum glove box by spin coating method Coated on the surface of the prepared SnO ₂ film, annealed at 120°C for 2 hours, and finally evaporated Al as an electrode using a vacuum evaporation apparatus, that is, an ITO/SnO ₂ :P3HT/Al inorganic/organic hybrid heterojunction was assembled Thin film solar cell devices. The device assembly diagram is shown in Figure 5.

The photoelectric performance of the assembled battery was tested by a solar simulator, AM1.5 filter, 100 mW/cm ² xenon light source for irradiation, and the photocurrent density-voltage curve (IV curve) of the battery was obtained, as shown in Figure 6. The open circuit voltage (Voc) of the battery is 0.405V, the photocurrent density (Jsc) is 0.321mA/cm ² , and the fill factor (FF) is 15.52%. The current photoelectric conversion efficiency of the battery is 0.02%.

Claims (4)

1. a hetero-junction thin-film solar cell device for inorganic/organic hybrid, is characterized in that, it is ITO/SnO ₂: P3HT/Al is inorganic/the hetero-junction thin-film solar cell device of organic hybrid; Wherein SnO ₂nano film material at low temperatures original position prepares, and method is with nanometer Sn ⁽⁰⁾for Xi Yuan, first utilize solvent structure SnS, then be predecessor water heat transfer SnO with SnS ₂film, to synthesize SnO by hydro-thermal and solvent heat two step wet chemical in the ITO electro-conductive glass substrate being coated with metallic tin ₂nano film material, this thin-film material thickness is regulated and controled by reaction temperature and reaction time condition.

2. as claimed in claim 1 a kind of inorganic/the hetero-junction thin-film solar cell device of organic hybrid, it is characterized in that: wherein SnO ₂the nano film material method that at low temperatures prepared by original position is, first magnetron sputtering is utilized to sputter layer of metal tin in the substrate of ITO electro-conductive glass, the ITO electro-conductive glass sheet inclined side this having been sputtered layer of metal tin is put in volume 30mL polytetrafluoroethylene reactor, make metal covering upward, add 3mg sulphur powder, then absolute ethyl alcohol and each 10mL of DMF is added, to be placed at 160 DEG C of temperature solvent thermal reaction 4 hours, product distilled water and absolute ethanol washing more than 2 times, be drying to obtain SnS film for subsequent use; Then the SnS film inclined side of preparation is put in 30mL polytetrafluoroethylene reactor, add 3mg ammonium persulfate as oxidant, to distill water as solvent, the volume of distilled water is vessel volume 1/2 ~ 2/3, react 24 hours under temperature is 140 DEG C of temperature, product distilled water and absolute ethanol washing more than 2 times, namely drying at room temperature obtains SnO ₂nano film material.

3. as claimed in claim 1 a kind of inorganic/the hetero-junction thin-film solar cell device of organic hybrid, it is characterized in that: wherein SnO ₂with the preparation method of P3HT hybrid heterojunctions thin-film solar cells be, first magnetron sputtering is utilized to sputter layer of metal tin in the substrate of ITO electro-conductive glass, the ITO electro-conductive glass sheet inclined side this having been sputtered layer of metal tin is put in volume 30mL polytetrafluoroethylene reactor, make metal covering upward, add 3mg sulphur powder, then absolute ethyl alcohol and each 10mL of DMF is added, to be placed at 160 DEG C of temperature solvent thermal reaction 4 hours, product distilled water and absolute ethanol washing more than 2 times, be drying to obtain SnS film for subsequent use; Then the SnS film inclined side of preparation is put in 30mL polytetrafluoroethylene reactor, add 3mg ammonium persulfate as oxidant, to distill water as solvent, the volume of distilled water is vessel volume 1/2-2/3, react 24 hours under temperature is 140 DEG C of temperature, product distilled water and absolute ethanol washing more than 2 times, namely drying at room temperature obtains SnO ₂nano thin-film;

Then in vacuum glove box, utilize spin-coating method that the P3HT of the 10mg/mL prepared is spun on obtained SnO ₂nano thin-film surface, 120 DEG C of annealing in process 2 hours and get final product.

4. as claimed in claim 1 a kind of inorganic/preparation method of the hetero-junction thin-film solar cell device of organic hybrid, it is characterized in that: first prepare SnO by the step described in claim 3 ₂with P3HT hybrid heterojunctions thin-film solar cells, recycling vacuum evaporation instrument steams and does electrode with Al, namely assembles to obtain ITO/SnO ₂: P3HT/Al is inorganic/the hetero-junction thin-film solar cell device of organic hybrid.