Design and performance optimization of carbon-based all-inorganic CsPbIBr2 perovskite battery with C60 buffer layer

The CsPbIBr2 material has obvious benefits in balancing the high efficiency and stability of carbon-based all-inorganic perovskite solar cells (PSC). However, the wide band gap of 2.08 eV and the serious carrier recombination between the interfaces limit the optical collection and carrier migration. In this work, based on the matching band structure of C60 and CsPbIBr2, the structure of FTO/In2S3/CsPbIBr2/C60/CuSCN/C is constructed in SCAPS-1D numerical analog quasi-software. The effect of C60 buffer layer structure on the properties of carbon-based all-inorganic CsPbIBr2 PSC was studied. It is found that the existence of the buffer layer increases the quantum efficiency of the device, and the power conversion efficiency (PCE) increases from 7.24 % to 10.01 %. In addition, in order to further enhance the carrier migration and reduce carrier recombination between the interfaces, this simulation achieved the highest PCE of 14.16 % by improving the band offset and optimizing the energy barrier structure between FTO/In2S3 and C60/CuSCN interfaces. To further study the change in device performance under a high-temperature working environment, this work set the temperature range to 300–400 K. It is found that when the working temperature is 340 K, the PCE and FF are 14.02 % and 70.66 %, respectively, which shows the high efficiency and stability of carbon-based inorganic CsPbIBr2 PSC. Hence, this work will provide an effective strategy for the manufacture of carbon-based all-inorganic PSC with high efficiency and long-term stability in a high-temperature environment.