Research On Energy Band Regulation And Device Structure Design Of Perovskite Solar Cells

Perovskite solar cells are considered as the most potential photovoltaic devices in the future because of their simple preparation and high photoelectric conversion efficiency.In the research of perovskite solar cells,improving its photoelectric conversion efficiency is of great significance to improve energy efficiency and reduce commercial cost.Based on the tunable band gap of perovskite materials,this paper proposes to increase the open circuit voltage of the device through the wide band gap perovskite absorption layer,broaden the spectrum absorption of the narrow band gap perovskite absorption layer,improve the short circuit current of the device,and then the photoelectric conversion efficiency of the device is improved.Therefore,a double layer perovskite absorption layer with broad band gap at the bottom layer and narrow band gap at the top layer was prepared,and the device performance was improved by optimizing the structure of perovskite solar cells..(1)In this paper,based on MAPbI3 system,the band gap of perovskite absorption layer is increased from 1.60 eV to 1.77 eV by adjusting the Br doping ratio.With the increase of the band gap of perovskite absorption layer,the open circuit voltage of perovskite solar cells increases,which can provide an ideal open circuit voltage for double-layer superimposed band gap perovskite solar cells.(2)A double layer band gap perovskite solar cell was prepared.The superposition of the top narrow band gap broadens the spectral absorption range of the perovskite solar cell and improves the short circuit current density.At the same time,the bottom wide band gap perovskite absorption layer provides a higher open circuit voltage and improves the conversion efficiency to 20.10%.(3)Based on the simulation,the structure of the double layer perovskite solar cell was optimized.By adjusting the band gap of the double layer perovskite absorption layer,the regulation and optimization mechanism of the photoelectric conversion efficiency of the device were obtained.