Study of Se/Te-doped Cu2O as a hole transport material in perovskite solar cells.

ABSTRACT

Theoretically, cuprous oxide (Cu2O) is a particularly excellent potential material, for the hole transport layer (HTL) of perovskite solar cells (PSCs). However, the photoelectric conversion efficiency (PCE) of its experimental samples is still not ideal. The main reasons for this include the material, and inherent and interface defects of Cu2O, but this can be improved by doping. In this research, Te- and Se/Te-doped Cu2O were experimentally and numerically studied to check the improvement of the material and interface properties. It was found that, for both the electrical and optical properties, the Se/Te-doped Cu2O performed considerably better than that which had been Te-doped and the pure Cu2O. Compared with the pure Cu2O thin film, the carrier mobility of the Se/Te-doped Cu2O thin film is improved from 60 cm2 V-1 s-1 to 1297 cm2 V-1 s-1, and the bandgap changed from 2.05 eV to 1.88 eV. According to the results calculated using solar cell simulation software SCAPS, the cell efficiency of the Se/Te-doped Cu2O is improved by 22% when compared to that of pure Cu2O. This efficiency can be further improved to 34% by optimizing the thickness of the Se/Te-doped Cu2O thin film and the defect density of states between the material interfaces.