Structure Simulation And Research Of Solar Cell Based On InGaAsP Quaternary Compound Material

Facing the complexity of space environment,the III-V multi-junction space solar cells play an important role in the field of spacecraft due to their high conversion efficiency,high temperature resistance and radiation resistance.Traditional lattice-matched（LM）three-junction cells have been widely used in space power systems.However,the large band gap between the middle cell and the bottom cell leads to current mismatch,so the development has gradually entered a bottleneck period.Obviously,there is an urgent need for multi-junction solar cells with four junctions or more junctions to further utilize the spectrum to improve cell conversion efficiency.Materials with a band gap of 1.0 e V have always been considered to be the best materials to bridge the gap difference and achieve better current matching.Bandgap-tunable InGaAsP quaternary compound is one of the most promising candidates for next-generation high-efficiency solar cell materials.Therefore,it is necessary to simulate solar cells containing InGaAsP material.Firstly,in order to better improve the conversion efficiency of 1.0e V InGaAsP single-junction solar cell,the doping concentration and thickness of its cap layer,window layer,emitter region,base region,BSF layer and buffer layer were optimized and analyzed.The optimization result of single junction solar cell without antireflection film are as follows:the open-circuit voltage V_OC=0.6503V,the short-circuit current density J_SC=34.5311 m A/cm~2,the fill factor FF=0.8253,and the conversion efficiencyη=13.5573%（under AM0,300K,1Sun）.The effects of temperature,surface recombination velocity between window layer and emission region and SRH composite minority carrier lifetime on the electrical performance of solar cells are studied respectively.The results show that in a certain range,the reduction of temperature and surface recombination velocity,the increase of minority carrier lifetime will improve the conversion efficiency of solar cells.Second,applying InGaAsP single junction solar cell to Ga In P/Ga As//InGaAsP/In Ga As four bonding solar cells.The influence of incident Angle and monolayer thickness on the average reflectivity of each subcell was investigated,and various anti-reflectivity film systems were designed to reduce the reflectivity of the absorption range.For Mg F₂/Al₂O₃/Ti₃O₅（refractive index:1.38/1.6/2.42,thickness:99.32/85.76/65.35nm）film system,Si₃N₄/Al₂O₃/Si₃N₄/Si O₂（refractive index:2.2/1.6/2.2/1.46,thickness:69.30/46.8/20.05/112.56nm）film system and Si C/Y₂O₃/Si O₂（refractive index:2.64/1.79/1.46,thickness:51.96/99.89/92.15nm）film system,low average reflectivity was achieved in the 300～1800nm band and the absorption light band of each subcell.Thirdly,the anti-irradiation effect of four-junction bonded solar cells was studied.The irradiation of electrons（low energy）and protons（low energy and high energy）was simulated by Casino and Srim software respectively.For low energy proton and electron irradiation,Ga In P cell damage is serious,for high energy proton irradiation,Ga As cell and InGaAsP cell damage is more acute.