Electronic structures and molecular dynamics of gadolinium-doped FAPbI3 perovskite crystals

Abstract

The additive effect of a gadolinium ion into a formamidinium lead iodide (FAPbI3) perovskite crystal on electronic structures and molecular dynamics was investigated for improving photovoltaic performance with stability. The electronic structures, band structure, partial density of state, and molecular dynamics were determined by first-principles calculation. The band distribution and charge transfer between the 5d orbital of the gadolinium atom, the 5p orbital of the iodine atom, and the 6p orbital of the lead atom promoted the carrier generation and diffusion related to short-circuit current density. The enthalpy and kinetic energy prompted stabilization of the gadolinium-doped crystal with a slight distortion of coordination structure, as compared with the decomposition of the FAPbI3 crystal. Diffusion coefficients of iodine and lead ions in the FAPbI3 crystal with defect were increased, predicting decomposition. The gadolinium-doped FAPbI3 perovskite crystal has great potential for applications in photovoltaic devices by improving photovoltaic performance.