Effect of Doping Concentration and Band Offset on the Efficiency of Homojunction Perovskite Solar Cells

In the field of renewable energy sources, perovskite solar cells have garnered significant attention thanks to remarkable power conversion efficiency and low fabrication cost. Among various attempts explored to enhance efficiency, p-n homojunction perovskite recently emerged as a promising approach. Leveraged from the inbuilt electric field inside the absorbing layer, it provides better charge separation and thus reduces the recombination. This paper presents an in-depth analysis of the homojunction perovskite solar cell performance with the p and n doping concentration as well as the effect of band offset at the junction between the perovskite and the electron and hole transport layer. The analysis shows that the band offset at the perovskite-electron transport layer interface plays the dominant role in the performance of the homojunction perovskite solar cell. The doping concentration on the two sides adds an extra degree of freedom in tailoring the band alignment and improving efficiency. The study can provide a better insight into designing a highly efficient homojunction perovskite solar cell with a proper choice of doping concentration and electron/hole transport layer.