Preparation And Modification Of TiO₂ Nanomaterial In The Perovskite Solar Cells

Since perovskite solar cells were invented in 2009,they have been becoming a rising star in photovoltaic field because of their simple preparation process and low cost.Although photoelectric conversion efficiency of these cells was rapidly developed from 3.8%to 22.7%,there is still a certain distance from it to 37%,theoretical limit of the efficiency,and it is still the focus of research in this field to improve battery efficiency.Researchers will improve the electron transport capacity of TiO2 porous materials as an important way to improve battery efficiency.It was shown that the modified TiO₂ nanocrystalline and porous layer were prepared by solvothermal method and sol-gel method in this paper.The effect of the porous material on efficiency of perovskite solar cell was studied,and its mechanism was analyzed in order to improve the transmission capacity of the photogenerate carrier in the perovskite solar cell,and the photoelectric conversion efficiency of the cells was improved.The main contents are as follows:1.The anatase TiO₂ porous material was prepared by titanium sulfate and oleic acid as the capping agent.The effect of titanium concentration on the micromorphology of porous layer and cell efficiency of perovskite solar cells were researched.TEM,SEM and XRD were used to characterize the microstructure of TiO₂ porous material prepared by different concentrations of titanium source,and being analyzed the formation mechanism.It was investigated to the influence mechanism of porous material on electron transport was analyzed from electrochemical point of view.The results are shown that the concentration of titanium source increased from 0.125mol·L^-1 to 1mol·L^-1,and the cell efficiency increased from 3.17%to 7.10%.It was considered that the increase of the concentration of titanium source has increased the size of the porous material and reduced the contact area with the absorption layer,but the increase of the high energy exposure surface of{001}improves the performance of the electron transport in the porous layer,and more electrons are transported to the surface to improve the performance parameters of the short circuit current of the battery2.The self-doped TiO₂ thin films used in perovskite solar cells are prepared by metals such as zinc,magnesium and aluminum as reducing agents.By studying electronic transmission performance and photocatalyst of solar cells of these samples with different reductive metals and concentration of morphology,it is shown that the electron transport properties and the highest efficiency of the perovskite cell is used self-doped TiO₂ as porous layer reduced by zinc,the fundamental reason is the material of the conduction band matched FTO conductive glass band level and the perovskite absorbing light layer band level.At the same time,the perovskite solar cell with low concentration of self-doped TiO₂ material has higher efficiency than high concentration,because the reducibility of catalytic metal can inhibit the transport of carriers.The main feature of this paper is to put to use a simple method to prepare the square TiO₂ as porous material of the perovskite solar cells,and to the self-doped TiO₂ of which the band was changed to improve the performance of perovskite solar cells.