Trapped Carrier Recombination in Sb2Se3 Polycrystalline Film

Sb2Se3 has recently emerged as a promising material for optic-electronic applications. In this work, trapped carrier recombination in Sb2Se3 was investigated by joint use of time-resolved microwave conductivity (TRMC) and photoluminescence (PL) spectroscopy. trapped carrier thermal excitation into the continuous band was observed in TRMC kinetics. Based on the exponential band tail model, the depth of the trap state, where trapped carriers are released into a continuous band, was estimated to range from 33.0 meV to 110.0 meV at room temperature. Temperature-varying TRMC and PL were further employed to study the influence of temperature on the trapped carrier recombination. Negative thermal quenchings of PL intensity and quantity of thermal emission carriers were observed and can be well explained by the thermal excitation of deep trapped carriers into shallow trap states and the continuous band. Two thermal activation energies of 12.5 meV and 304.0 meV were also revealed. This work is helpful for understanding the trapped carrier recombination process in polycrystalline Sb2Se3 film.