Scalable Fabrication of Bi2O2Se Polycrystalline Thin Film for Near-infrared Optoelectronic Devices Applications

We present a controlled, stepwise formation of layered semiconductor Bi2O2Se thin films prepared via the vapour process by annealing topological insulator Bi2Se3 thin films in low oxygen atmosphere for different reaction. Photodetectors based on Bi2O2Se thin film show a responsivity of 1.7×104 A/W at a wavelength of 980 nm. Field-effect transistors based on Bi2O2Se thin film exhibit n-type behaviour and present a high electron mobility of 17 cm2/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 Bi2O2Se thin films. From the obtained results, it is evident that low oxygen annealing is a surprisingly effective method to fabricate Bi2O2Se thin films for integrated optoelectronic applications.