CN106169537A - Preparation method of solar cell - Google Patents

Abstract

The invention discloses a preparation method of a solar cell, wherein the solar cell is obtained by processing a silicon wafer, spin-coating a passivation layer solution and a PEDOT (polyethylene glycol terephthalate) PSS (Polytetrafluoroethylene) aqueous solution and evaporating, the passivation layer solution is a titanium oxide precursor solution, and the titanium oxide precursor solution is prepared by the following method: 1. dispersing titanium isopropoxide in isopropanol solution, diluting, stirring to uniformly disperse the titanium isopropoxide to prepare solution I; 2. diluting the hydrochloric acid solution by using isopropanol, then dropwise adding the diluted hydrochloric acid solution into the solution I, and stirring to obtain a solution II; the prepared solution II is spin-coated on the treated silicon wafer. The manufacturing process is simple, and the manufactured solar cell has good physical properties.

Description

A kind of preparation method of solar cell

technical field

The invention relates to the technical field of photoelectric devices, in particular to a method for preparing a solar cell.

Background technique

Energy is the driving force for the development of human society. With population growth and economic development, energy consumption will more than double by mid-century. Most of the energy currently used comes from fossil fuels, and the proportion of other energy sources is relatively small. However, the amount of fossil fuels is limited, difficult to regenerate, and their use will cause huge pollution to the environment. Therefore, it has become a global consensus to change the energy structure, use clean new energy, and protect the earth. The current clean energy mainly includes hydrogen energy, biomass energy, solar energy and wind energy. Among them, solar energy is the energy radiated to the outside world by nuclear fusion inside the sun. The energy it provides to the earth for one hour can be used by human society for one year, and the solar radiation energy reaching the ground in one year is equivalent to one billion tons of coal energy Human beings have tens of thousands of times the energy provided by various energy sources in the same period. Therefore, as a kind of green renewable energy, solar energy is inexhaustible and inexhaustible. It has a huge source and high security, and will be the supporting energy with the most development potential in the future.

In the utilization of solar energy, solar cells are one of the most promising renewable energy generation directions. Solar cells are electronic devices that convert sunlight energy into electrical energy. At present, there are many kinds of solar cells. According to different materials, they can be divided into: the first generation of crystalline silicon solar cells, mainly monocrystalline silicon cells and polycrystalline silicon cells; the second generation of thin film solar cells, mainly silicon-based thin film cells, III-V group Compound batteries, Ⅱ-Ⅵ compound batteries, copper indium gallium selenium batteries and copper zinc selenium sulfur batteries, etc.; third-generation solar cells, mainly dye-sensitized solar cells, organic solar cells, quantum dot solar cells, perovskite solar cells and hybrid solar cells.

Among many solar cells, silicon cells account for 90% of the market share and have always been a research hotspot of solar cells. However, a prominent problem facing silicon batteries is that due to the large number of defect states between the interfaces, the recombination of carriers at the interface is serious, resulting in a lack of device performance. At present, for the research on reducing carrier interface recombination, silicon oxide, silicon nitride, amorphous silicon, titanium oxide, aluminum oxide and other materials are mainly used to modify and passivate the interface. However, the above-mentioned methods generally require a relatively complicated process to achieve effective passivation of the silicon surface, which requires high equipment and relatively high prices. Therefore, the research and development of a process that can realize surface passivation by using a simple process has important application value for further reducing the cost of silicon solar cells.

In view of the above-mentioned defects, the designer is actively researching and innovating, in order to create a method for preparing solar cells, so that it has more production value.

Contents of the invention

In order to solve the above technical problems, the object of the present invention is to provide a method for preparing a solar cell with low production cost, simple operation process and good physical properties.

Technical problem of the present invention is mainly solved through the following technical solutions:

The invention discloses a method for preparing a solar cell. The solar cell is obtained by treating a silicon wafer, spin-coating a passivation layer solution and a PEDOT:PSS aqueous solution, and evaporating. The passivation layer solution is a titanium oxide precursor The titanium oxide precursor solution is prepared by the following method: (1) disperse titanium isopropoxide in isopropanol solution and dilute, stir to make it uniformly dispersed, and prepare solution I; (2) use hydrochloric acid solution Diluted with isopropanol, then added dropwise to solution I and stirred to obtain solution II; the prepared solution II was spin-coated on the treated silicon wafer.

Further, the titanium oxide precursor solution is prepared at a temperature lower than 200°C.

Further, the processing of the silicon wafer includes the following steps: (1) After cleaning the silicon wafer with a resistance value of 0.05-0.1Ω/cm ² , immerse it in a mixed solution of 0.2M AgNO3 and 4.8M HF and etch for 5 minutes, Then use deionized water to clean; (2) Soak the treated silicon chip with concentrated nitric acid for 5 minutes, take it out, wash and dry it; (3) immerse the processed silicon chip in HF solution for 2 minutes, and then place Etching in 1% tetramethylammonium hydroxide solution for 40 seconds.

Further, the solution II is spin-coated on the lower surface of the treated silicon wafer, the PEDOT:PSS aqueous solution is spin-coated on the upper surface of the silicon wafer, and annealing is performed to form PEDOT:PSS on the upper surface and the lower surface of the silicon wafer respectively. Conductive thin film and titanium oxide passivation layer.

Further, the PEDOT:PSS aqueous solution is obtained by mixing PEDOT:PSS polymer with a conductivity of 1000, DMSO organic compound and Triton X-100 nonionic surfactant in a ratio of 94:5:1.

Further, the treated silicon wafer is annealed at a temperature of 150° C., and spin-coated at a speed of 3000 rpm for 1 minute.

Further, the anode electrode and the cathode electrode are respectively deposited on the surface of the PEDOT:PSS conductive film and the titanium oxide passivation layer through the evaporation method.

Further, the anode electrode is a grid-shaped silver electrode with a thickness in the range of 190-210 nm, and the cathode electrode is an aluminum electrode with a thickness in the range of 190-210 nm. .

By means of the above scheme, the precursor solution method provided by the present invention to prepare the oxide passivation layer, compared with the conventional atomic layer deposition, high temperature thermal oxidation growth, chemical deposition method, etc. to prepare the passivation modification layer, has at least the following advantages :

1. The preparation process is simple, and solution processing such as spin coating, spray coating, screen printing, printing and other methods can be used, and the equipment requirements are relatively low, which is conducive to the realization of large-area preparation;

2. The temperature of the oxide preparation process is lower than 200 degrees Celsius, which is conducive to greatly reducing the processing cost of solar cells;

3. Using the good passivation properties of oxides, the defect states of silicon wafers are reduced, which is beneficial to improve short-circuit current and open-circuit voltage;

4. The selected oxide dispersing solvent is less harmful to the body and the environment and is safer.

The above description is only an overview of the technical solutions of the present invention. In order to understand the technical means of the present invention more clearly and implement them according to the contents of the description, the preferred embodiments of the present invention and accompanying drawings are described in detail below.

Description of drawings

Fig. 1 is the structural representation of the silicon-organic hybrid solar cell that embodiment case obtains;

Fig. 2 is the I-V curve of the silicon-organic hybrid solar cell that embodiment case obtains;

Fig. 3 is the external quantum efficiency curve of the silicon-organic hybrid solar cell obtained by the implementation case;

Fig. 4 is the minority carrier lifetime curve of the silicon-organic hybrid solar cell obtained by the implementation case;

In the above figures, the IV curve is measured under the irradiation of 100mW/cm ² AM1.5 solar simulator.

detailed description

The specific implementation manners of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Example:

The steps of a method for preparing a solar cell provided in this embodiment are as follows:

(1) Clean the silicon wafer and etch the structure; the specific steps include: 1. After cleaning the silicon wafer with a resistance value of 0.05-0.1Ω/ ^cm2 , immerse it in a mixed solution of 0.2M AgNO3 and 4.8M HF to etch etched for 5 minutes, and then cleaned with deionized water; 2. Soak the treated silicon wafer in concentrated nitric acid for 5 minutes, take it out and wash and dry it; 3. Submerge the treated silicon wafer in HF solution for 2 minutes, and then Place in a 1% tetramethylammonium hydroxide solution and etch for 40 seconds. The present invention uses silicon-organic hybrid solar cells as battery implementation examples, and the scope of solar cells is not limited to silicon-organic hybrid solar cells, including all silicon-based solar cells, solar cells such as monocrystalline silicon, polycrystalline silicon, and thin-film silicon.

(2) Preparation of titanium oxide precursor solution: Dilute titanium isopropoxide in isopropanol solution, stir for 5 minutes to make it uniformly dispersed, and prepare solution I. The hydrochloric acid solution was diluted with isopropanol, then added dropwise to solution I, and stirred for 3 hours to obtain solution II. Titanium oxide precursor solution is used as an oxide solution. The range of oxide precursor solutions is not limited to titanium oxide precursor solutions, including aluminum oxide, silicon oxide, titanium oxide, molybdenum oxide, niobium oxide, zinc oxide, and tin oxide. oxide. An implementation case of using titanium isopropoxide as the raw material for the preparation of the titanium oxide precursor solution. The range of raw materials for the preparation of the titanium oxide precursor solution is not limited to titanium isopropoxide, including titanium isopropoxide, tetrabutyl titanate, and titanium tetrachloride and other alkyl titanium compounds.

(3) Spin-coat the titanium oxide precursor solution on the lower surface of the silicon wafer: Spin-coat solution II on the lower surface of the silicon wafer treated with hydrofluoric acid at a speed of 3000 rpm, and the spin-coating time is 1 minute. Anneal at 150°C for 30 minutes, the oxide precursor solution is hydrolyzed during the annealing process to form an oxide film, and generate Si-O-M bonds (M refers to metal) on the surface of the silicon wafer to reduce dangling bonds and defects on the surface of the silicon wafer state, realize the passivation of the surface of the silicon chip, improve the lifetime of minority carriers on the silicon surface, increase the short-circuit current, open-circuit voltage, and finally improve the efficiency of the device.

(4) After mixing PEDOT:PSS with a conductivity of 1000, DMSO organic compound and Triton X-100 nonionic surfactant in a ratio of 94:5:1, stir evenly, and anneal at 150 degrees Celsius for 30 minutes, The PEDOT:PSS conductive thin film was deposited on the upper surface of the silicon wafer by spin coating method with a rotation speed of 3000 rpm and a spin coating time of 1 minute.

(5) Deposit the grid-shaped anode silver electrode on the surface of the PEDOT:PSS conductive film by vacuum evaporation, with a thickness of 190-210nm.

(6) Depositing the cathode aluminum electrode on the titanium oxide through vacuum evaporation to obtain a silicon-organic hybrid solar cell with a passivation layer.

The structure of the silicon-organic hybrid solar cell is shown in Figure 1. From top to bottom, there are grid-shaped anode electrode, organic polymer (PEDOT:PSS film), n-type silicon substrate (light-absorbing layer), titanium oxide Aluminum electrode with cathode.

At room temperature, combined with the IV curve of the silicon-organic hybrid solar cell shown in Figure 2, it can be seen that the short-circuit current of the prepared silicon-organic hybrid solar cell is 30.67mA/cm ² , and the open-circuit voltage is 643mV; The external quantum efficiency curve of the silicon-organic hybrid solar cell shown in Figure 3 and the minority carrier lifetime curve of the silicon-organic hybrid solar cell shown in Figure 4, it can be seen that the prepared silicon-organic hybrid The filling factor of the solar cell is 0.72, the photoelectric conversion efficiency is 14.22%, and the maximum external quantum efficiency exceeds 90%.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention. It should be pointed out that for those of ordinary skill in the art, some improvements can be made without departing from the technical principle of the present invention. and modifications, these improvements and modifications should also be considered as the protection scope of the present invention.

Claims (8)

1. a preparation method for solaode, described solaode is by silicon chip is treated, spin coating passivation layer solution And obtain after PEDOT:PSS aqueous solution, evaporation, it is characterised in that: described passivation layer solution is titania precursor liquid solution, institute State titania precursor liquid solution to be prepared via a method which:

(1) isopropyl titanate is dispersed in aqueous isopropanol dilution, stirring so that it is be uniformly dispersed, prepare solution I；

(2) hydrochloric acid solution is used isopropanol, be then added drop-wise in solution I, stirring, it is thus achieved that solution II；

The solution II prepared is spin-coated on silicon chip after treatment.

The preparation method of a kind of solaode the most according to claim 1, it is characterised in that: described titania precursor body Solution is prepared at a temperature of less than 200 DEG C.

The preparation method of a kind of solaode the most according to claim 1, it is characterised in that: the process bag of described silicon chip Include following steps: resistance value is 0.05-0.1 Ω/cm by (1)²Wafer Cleaning after be dipped in 0.2M AgNO3's and 4.8M HF Mixed solution etches 5 minutes, then utilizes deionized water to clean；(2) the silicon chip concentrated nitric acid after processing soaks 5 minutes, Clean after taking-up and dry up；(3) silicon chip after processing again is immersed in HF solution 2 minutes, is subsequently placed in the tetramethyl that concentration is 1% Base Ammonia etches 40 seconds.

The preparation method of a kind of solaode the most according to claim 1, it is characterised in that: by the spin coating of described solution II Silicon chip lower surface after treatment, is spun to silicon chip upper surface by PEDOT:PSS aqueous solution, makes annealing treatment, on silicon chip PEDOT:PSS conductive film and titanium oxide passivation layer is formed respectively on surface and lower surface.

The preparation method of a kind of solaode the most according to claim 4, it is characterised in that: described PEDOT:PSS water Solution be by PEDOT:PSS high molecular polymer, DMSO organic compound and the Triton X-100 that conductivity is 1000 non-from Subtype surfactant obtains after mixing with the ratio of 94:5:1.

The preparation method of a kind of solaode the most according to claim 4, it is characterised in that: the silicon chip after described process Make annealing treatment at a temperature of 150 DEG C, spin coating 1 minute under the rotating speed of 3000 revs/min.

The preparation method of a kind of solaode the most according to claim 4, it is characterised in that: by anode electrode and negative electrode Electrode, through the mode of described evaporation, deposits on PEDOT:PSS conductive film surface and titanium oxide passivation layer respectively.

The preparation method of a kind of solaode the most according to claim 7, it is characterised in that: described anode electrode is grid Shape silver electrode, thickness range is 190-210nm, and described cathode electrode is aluminum electrode, and thickness range is 190-210nm.