Scalable fabrication of Bi_(2)O_(2)Se polycrystalline thin film for near-infrared optoelectronic devices applications

We present a controlled,stepwise formation of layered semiconductor Bi_(2)O_(2)Se thin films prepared via the vapour process by annealing topological insulator Bi_(2)Se3 thin films in low oxygen atmosphere for different reactions.Photodetectors based on Bi_(2)O_(2)Se thin film show a responsivity of 1.7×10^(4) A/W at a wavelength of 980 nm.Field-effect transistors based on Bi_(2)O_(2)Se thin film exhibit n-type behavior and present a high electron mobility of 17 cm^(2)/V·s.In addition,the electrical properties of the devices after 4 months keeping in the air shows little change,implying outstanding air-stability of our Bi_(2)O_(2)Se thin films.From the obtained results,it is evident that low oxygen annealing is a surprisingly effective method to fabricate Bi_(2)O_(2)Se thin films for integrated optoelectronic applications.