Carrier Nonradiative\nRecombination in Sb<sub>2</sub>Se<sub>3</sub>

Antimony selenide (Sb<sub>2</sub>Se<sub>3</sub>) is emerging\nas\nan optically active material for optoelectronic devices. Understanding\nthe carrier nonradiative recombination processes in Sb<sub>2</sub>Se<sub>3</sub> is crucial for the improvement of devices’\nperformance. In this work, the carrier nonradiative recombination\nwas investigated by transient absorption spectrum on the broad time\nscale from hundred femtoseconds to several microseconds. The evolution\nof the transient absorption spectrum has been associated with the\nfree carrier and trapped carrier recombination process. Our temperature\nvarying transient absorption spectrum measurement also confirmed that\nthe free carrier recombination in Sb<sub>2</sub>Se<sub>3</sub> is\ninsensitive to temperature. Finally, the rate equation for free carrier\nrecombination in Sb<sub>2</sub>Se<sub>3</sub> was discussed. To simulate\nthe free carrier decay well and interpret its temperature-insensitive\ncharacter, trap-assisted Auger recombination was introduced into the\nrate equation.