Controlled synthesis of high crystallization Bi2O2Se film and its photoelectric properties

Bi 2 O 2 Se 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 Bi 2 O 2 Se 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 Bi 2 O 2 Se was obtained. And the nucleation and selenylation mechanisms of Bi 2 O 3 were revealed based on the effect of temperatures modificatives growth of Bi 2 O 2 Se. 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 Bi 2 O 2 Se. 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.