| At present,China's modern traditional industrial fossil energy is faced with the issues of natural energy exhaustion and severe environmental contamination.Solar energy as a new type of energy,due to it has the advantages of clean,no pollution,renewable and so on has been widely used.The most efficient use of solar energy has become the focus of researchers in quite a few countries around the world.Perovskite batteries have aroused a global research upsurge because of their three advantages,such as advanced preparation technology,easy operation and low production cost.The first perovskite solar cell(Shorthand for PSCs)has been successfully flourished with a photoelectric conversion efficiency of 3.8%.Since that,researchers have refined and optimized the conversion efficiency.The addition of buffer layer greatly improves the energy level matching between the functional layers in the perovskite solar cell,and at the same time,the transport efficiency of the carrier is also improved,and the efficiency of the cell is also increased.The CdS buffer layer is the most widely studied at present.Nevertheless,due to the large absorption of CdS in the short-wave region,the further improvement of the performance of solar cells is limited.Moreover,cadmium sulfide contains Cd elements,which will damage the ecological environment.Therefore,the non-cadmium buffer has become a heated research topic of perovskite solar cells.This paper mainly explores the preparation conditions of two kinds of Cadmium-free buffer layer materials(ZnS and administered TiO2),and uses ZnS and TiO2 as the battery buffer layer respectively to prepare PSCs.The research of this paper mainly includes the following two aspects:1.ZnS thin films were prepared by chemical bath deposition.The variation of film quality under different deposition time was studied.By comparing the experimental results before and after annealing,the influence of thermal treatment on the film was explored.The corresponding perovskite cells were prepared and characterized.The experimental and analytical results represent that the surface of the films deposited with shorter deposition time is rougher,with many defects and poor quality.The transmittance of the film is about 80%.When the deposition time exceeds a certain value,the thickness of the film is thicker,but there are some large particles agglomerated on the surface of the film,which has a great impact on the optical properties of the film.It was found that when the preparation time was 30 min,the quality of the film prepared was good.When the film was added to the perovskite solar cell as a buffer layer,the photoelectric conversion efficiency of the cell was the best.The main parameters of PSCs obtained are as follows:Short circuit current density is 19.99 mA/cm2,the open circuit voltage is 1060 mV,fill factor is 0.70,and efficiency Photoelectric conversion efficiency is 14.86%.2.TiO2 films were prepared by electrophoretic deposition method,and PSCs were prepared by using TiO2 as the buffer layer under different electrophoretic deposition times.The effect of deposition times and annealing on the efficiency of the cell was studied by comparing the efficiency of the cell.The experimental results show that when the electrophoretic deposition method is used to prepare the TiO2 nanosheet film,the contact between the film and the functional layer is poor,the film forming effect is poor,and the film quality is poor.When the number of deposition times is large,due to the increase of the thickness of the film,the electric adsorption of the transparent electrode on the nanosheet decreases,leading to the uneven surface of the film.It was found that when the deposition times were three times,the composite properties of the films deposited were good and the efficiency of the perovskite solar cells prepared was high.The cell efficiency is 12.71%,Jsc=19.24 mA/cm2,VOC=1060 mV,FF=0.62.After annealing,the impurity of the film is reduced,the Jsc and VOC are increased,and the efficiency is up to 15.20%. |
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