Observation of bimolecular recombination in high mobility semiconductor Bi_2O_2Se using ultrafast spectroscopy

摘要

Bi2O2Se is emerging as a high mobility functional material for optoelectronics, but its fundamental optical properties remain less well studied. Here, ultrafast photocarrier dynamics in single crystal Bi2O2Se is investigated by pump fluence- dependent, broadband ultrafast spectroscopy. Our results reveal that bimolecular recombination plays an important role in the photocarrier relaxation process, and a room- temperature bimolecular recombination constant of (1.29+/-0.42) X 10(-9) cm(-3) s(-1) is obtained for Bi2O2Se. Such a level of the recombination constant combined with a high mobility (similar to 1006cm(2) V-1 s(-1) at 200K for Bi2O2Se) suggests that Bi2O2Se can be a promising material for photovoltaic applications. Published by AIP Publishing.