Controlled synthesis of high crystallization Bi2O2Se film and its photoelectric properties

Abstract

Bi2O2Se has attracted a lot of attention in the field of photodetection due to its ultra-high mobility and tunable band gap. However, the mechanism of controllable preparation of high-quality Bi2O2Se is unclear and needs further investigation. In this paper, the concentration of reactants in the substrate region was increased by the method of space-compression, the number of nucleation was effectively controlled, and larger size Bi2O2Se was obtained. And the nucleation and selenylation mechanisms of Bi2O3 were revealed based on the effect of temperatures modificatives growth of Bi2O2Se. And the controlled growth was achieved in a certain thickness range by increasing the reactant concentration in the substrate region and controlling the nucleation number. Moreover, photodetectors were constructed based on the highly crystalline Bi2O2Se. The photodetector exhibited a photoresponsivity of up to 9550 A/W under the excitation of 405 nm light and obtained highly stable and recoverable characteristics with multiple laser switches.