Design And Simulation Of Heterojunction Full-back Solar Cells

As one of the most promising directions for the development of new energy,solar energy has received widespread attention.Photovoltaic field,as the main direction of solar energy development at present,is one of the industries in which my country is in an international leading position in the field of new energy.In order to realize the further development of my country’s photovoltaic industry,the development of more efficient and cheap solar cells is its core.At present,the single-cell silicon-based solar cell with the highest conversion efficiency is the heterojunction full-back solar cell,so the related research on it is needed by my country’s photovoltaic industry.In this thesis,the silicon heterojunction full-back solar cell is firstly modeled and simulated,and the influence of its structural parameters on the performance of the cell is analyzed.On this basis,the effects of silicon wafer bulk lifetime and surface recombination velocity on the performance of wide interdigitated cells with N-region width of 0.5 mm and P-region width of 1.3 mm were investigated.At the same time,a buried gate electrode battery structure that can simplify the battery process is designed and simulated.Afterwards,a MoO_x-based silicon-based undoped heterojunction full-back cell was designed and the effect of its structural parameters on the performance was studied by simulation.Finally,combined with silicon heterojunction and undoped heterojunction,a buried gate electrode full-back cell structure based on electron/hole transport layer and silicon heterojunction is designed and simulated.The main research work is as follows:（1）A simulation model of an amorphous silicon/single crystal silicon heterojunction full-back solar cell was designed and established,and the influence of various structural parameters on the performance of the cell was studied in detail.The efficiency is 12 ms bulk life,0.1 cm/s surface The compound speed can reach 26.34%.The influence of silicon wafer bulk life and surface recombination speed on its performance under the two conditions of wide/fine interdigitated cell is simulated and analyzed,and it is found that when the silicon wafer bulk life and surface recombination speed meet the requirements,even if the interdigitated cell is the smallest.A width of 0.5 mm still has the ability to exceed 25%efficiency.（2）A buried-gate electrode cell structure that can be fabricated by only one photolithography is designed,and the cell structure is modeled and simulated.Its efficiency can reach 25.46%at 6 ms bulk lifetime of silicon wafer and 1 cm/s surface recombination velocity.This efficiency can reach 26.44%under the ideal conditions of12 ms bulk lifetime and 0.1 cm/s surface recombination velocity.（3）A MoO_x-based silicon-based undoped heterojunction full-back battery is designed and simulated.The results show that the efficiency can reach 26.34%when the work function of the metal electrode,the life of the silicon wafer and the surface recombination speed are ideal.Finally,combined with undoped heterojunction and silicon heterojunction,a full-back cell with buried gate electrode structure based on electron/hole transport layer and silicon heterojunction was designed and simulated and analyzed.The results show that it has the ability to convert more than 25% efficiency.