Application Of Hydrotalcite Pyrolysis Products In Perovskite Solar Cells

With the worldwide economic development and population growth,conventional fossil fuels,such as coal,oil,and natural gas,have been depleted and will be exhausted,which causes serious environmental problems.Therefore,new renewable energy sources are very demanding for the future development of the world.Solar energy is undoubtedly the best choice.Perovskite solar cells(PSCs)are new types of organic-inorganic composite thin-film solar cells that have reached 22%energy conversion efficiency in recent years and are expected to be the next generation of clean energy that can be used in our lives.However,the stability of this solar cell material has become a bottleneck restricting its further application.Various studies have been carried out to improve its stability.The aim of this paper is to fabricate the perovskite solar cell with TiO2 as electron transport layer and the MAPbI3 perovskite as light harvesting layer by one-step solvent and two-step deposition method,to compare the structure and performance of perovskite.The prepared process was optimized and the impact factor on the cell efficiency was discussed.Moreover,the pyrolysis product of Zn-Al layered double hydroxides(LDHs)was employed as the electron transport layers in the MAPbI3 perovskite solar cell.The main content can be summarized as the following:(a)It is necessary to find a suitable method to prepare the perovskite layer for improving the photovoltaic efficiency of the solar cell.The tetraisopropyl titanate was hydrolyzed and spin-coated into dense TiO2 layer on FTO glass,mesoporous TiO2 was also spin-coated as a mesoporous layer for loading MAPbI3 and the commercial carbon paste were used as a counter electrode.The solar cell infrastructure was,FTO/dense TiO2/meso-TiO2/MAPbI3/C,The MAPbI3 layers was prepared by the one-stop and two-step method,respectively.The structure,morphology and photovoltaic effects was compared for the solar cell with different MAPbI3 loading method.We find that prepared of perovskite solar cell with one step method,the efficiency is 1.28%,but the efficiency reached 6.62%for solar cell with two-step method,it can be concluded that the two-step method is better than one-step one for the solar cell.(b)The photovoltaic performance of MAPbI3 perovskite solar cells with Zn-Al MMO nanosheets as electron transport layer was prepared and systematic studied.The Zn-Al LDHs was prepared by the hydrothermal method and employed as the dense layers,then the MAPbI3 perovskite was coated on the meso-TiO2 layers by two-step deposition method,the carbon electrode being used as the counter electrode.Furthermore,the metal ratio,the annealing temperature for the Zn-Al LDHs were investigated to obtain the optimal pyrolysis oxide products for improving the photovoltaic performance of the solar cell.The effect of its use as an electron transport layer on the performance of perovskite solar cells was explored.It was found that at 500°C and 600°C pyrolysis the optimum efficiency of the cell device was 6.60%when the molar ratio of zinc to aluminum was 5.It has been reported so far that Zn-Al MMO has achieved the highest efficiency as an electron transport material in PSCs.