Structural Design Of Perovskite/Crystalline Silicon Tandem Solar Cells

Traditional single-junction solar cells,which only utilize one kind of lightabsorption material,cannot fully utilize the energy of the solar spectrum,resulting in a theoretical maximum efficiency of only 33%.The improvement space of singlejunction solar cells is mainly limited by the bandgap of the light absorption material.Perovskite/crystalline silicon tandem solar cells can more fully utilize the solar spectrum,with a theoretical maximum efficiency greater than 40%,and the laboratory conversion efficiency has surpassed 32.5%.It also has the advantages of low cost and customizability.Perovskite/c-Si tandem solar cells have attracted significant attention in the photovoltaic industry and are one of the main technological trends in the future.This paper focuses on the structural design of methylammonium lead iodide/silicon heterojunction(MAPbI3/SHJ)tandem solar cells using the solar cell simulation software wxAMPS.The study investigates the influence of the thickness,doping concentration,and defect density of the light-absorbing layers on the performance of tandem solar cells to obtain an optimized structure.The specific contents include:(1)Establishing simulation models for single-junction solar cells based on MAPbI3 perovskite and SHJ.The solar cell structure is optimized in terms of the thickness,doping concentration,and defect concentration of each functional layer to obtain the optimal structure for the single-junction solar cell.(2)Using the optimized designs of the two single-junction solar cells,simulation models for the MAPbI3/SHJ tandem solar cell are established.The current matching of the tandem solar cell is achieved by adjusting the thickness of the light-absorbing layers in the upper and lower sub-cells,leading to the development of a performanceoptimized tandem solar cell device.The main research findings of this paper are as follows:(1)The optimal structure for the perovskite solar cell FTO/TiO2/MAPbI3/SpiroMeOTAD/Au is determined as follows:thicknesses of TiO2,MAPbI3,and SpiroMeOTAD are 0.1 μm,0.9 μm,and 0.05 μm,doping concentrations are 1×1020 cm-3,1×1014 cm-3,and1×1019 cm-3,and defect concentrations are 1×1015 cm-3,1×1014 cm-3,and 1×1018 cm-3,respectively.The optimized structure achieves a power conversion efficiency of 27.26%,with a short-circuit current of 22.52 mA/cm2,open-circuit voltage of 1.37 V,and fill factor of 88.16%.(2)The optimal structure for the silicon heterojunction solar cell Ag/a-Si:H(n+)/aSi:H(i)/c-Si(p)/a-Si:H(i)/a-Si:H(p+)/Ag is determined as follows:thicknesses of aSi:H(n+),c-Si(p),and a-Si:H(p+)are 0.01 μm,200 μm,and 0.01μm,doping concentrations are 1×1018 cm-3,1×1015 cm-3,and 1×1019 cm-3,defect concentrations were 1×1016 cm-3,1×1014 cm-3,and 1×1016 cm-3,respectively.The optimized structure achieves a power conversion efficiency of 24.24%,with a short-circuit current of 41.77 mA/cm2,open-circuit voltage of 0.69 V,and fill factor of 83.88%.(3)When the MAPbI3 and c-Si(p)light-absorbing layer thicknesses in the MAPbI3/SHJ tandem solar cell are 0.18 μm and 167μm respectively,current matching of the sub-cells is achieved.Under these conditions,the tandem solar cell exhibits a short-circuit current of 16.45 mA/cm2,open-circuit voltage of 2.09 V,fill factor of 93.39%,and a remarkably high power conversion efficiency of 3 2.11%.This research paper provides a theoretical basis and valuable reference for understanding the design and structural optimization of perovskite/crystalline silicon tandem solar cells.