Preparation And Characterization Of Perovskite/Crystalline Silicon Tandem Solar Cell

The direct band gap of the perovskite can be adjusted continuously and preparation cost is very low,which make it become the best light absorption layer material of the top solar cell in Si-based Low preparation costtandem solar.What's more,the direct band gap of perovskite is 1.6¹.8eV,which is very suitable to fabricate a tandem solar cell.This paper mainly uses the CH₃NH₃PbI₂Br perovskite as the light absorption layer in the top solar cell which has stable performance in the atmospheric environment and band gap of1.77eV.This paper mainly studies the preparation of each layer in the top cell,simulation and optimization for the 2-terminal perovskite/crystalline silicon tandem solar cell.The main research works are as follows:1.CH₃NH₃PbI₂Br perovskite thin film was prepared by using the one step solution method under the atmosphere,and influence of annealing temperature on the characteristic of the thin was studied.It finds that the thin film showed branch structure,and was poor light absorption and discontinuous because of the rapid solvent evaporation.By adding CH₃NH₃Cl in the precursor solution,intermediate product was formed so that it slowed down the rate of peovskite crystal.Thus,the coverage in and light absorption characteristics were increased and the impact of additive CH₃NH₃Cl on the formation of perovskite films was analyzed.In addition,the crystallinity,continuity and optical absorption properties of the film are better when the annealing temperature is 100?.However,excessive annealing temperature?>120??will cause the decomposition of CH₃NH₃PbI₂Br.At the same time,it is proved that the optical band gap is not affected by the annealing temperature.2.ZnO thin films were prepared by magnetron sputtering.Effects of different sputtering time on the performance of ZnO and perovskite solar cell without hole transport layer were explored.When the sputtering time is 15min,that is to say,the film thickness is61.8nm,ZnO has good optical properties,and cell efficiency is 0.558%.3.The Silvaco Altas software is used to simulate perovskite/c-Si tandem solar cell,which discuss mainly the effect of the thickness of CH₃NH₃PbI₂Br and NiOx thickness and tunnel junction on the performance of tandem solar cell.For the top solar cell without hole transport layer,when the light absorption layer thickness is 200nm,the doping concentration of tunnel junction is 5*10¹⁸cm^-3,and tunnel junction thickness is 2*10nm,it implements the current matching so that the performance can reach the best.The optimized efficiency is 12.134%,open circuit voltage is 0.9V,short-circuit current is25.21072mA/cm².4.The simulation results show that,by adding NiOx in the top cell as hole transport layer,the characteristic of tandem solar cell is improved.When the thickness of NiOx is30nm,the characteristic of solar cell is the best.By adjusting to the thickness of CH₃NH₃PbI₂Br and the concentration of the tunnel junction,it shows that when the thickness of CH₃NH₃PbI₂Br is 500nm,doping concentration of tunnel junction is1*10¹⁹cm^-3,the efficiency is the best.The optimized efficiency can reach 30.850%.