Transfer-Free Growth of Bi<sub>2</sub>O<sub>2</sub>Se on Silicon Dioxide via Chemical Vapor Deposition
Rizwan Ur Rehman Sagar, Usman Khan, Massimiliano Galluzzi, Sehrish Aslam, Adeela Nairan, Tauseef Anwar, Waqas Ahmad, Min Zhang, Tongxiang Liang
Abstract
The bismuth oxyselenide (Bi2O2Se) is considered as an alternative to graphene (zero band gap), black phosphorus, and molybdenum sulfide (MoS2) due to its sizeable band gap and high carrier mobility. To date, Bi2O2Se is fabricated on the top of mica using two to three sources under dual heating zones inside a chemical vapor deposition tube followed by its transfer on a desired substrate for particular device application. Herein, we have proposed an entirely new growth mechanism to synthesize Bi2O2Se directly on silicon dioxide (SiO2) using single source bismuth selenium (Bi2Se3) to get rid of the transfer process. The as-grown Bi2O2Se flakes were mechanically, structurally, and topographically investigated to ensure the quality of flakes. Young’s modulus ∼ 65 GPa of as-grown Bi2O2Se is thickness dependent, indicating the successful fabrication of Bi2O2Se on SiO2 as the Young’s modulus of Bi2Se3 ∼ 44–58 GPa is far lower than that of Bi2O2Se. The structure of as-synthesized Bi2O2Se provided evidence of successful fabrication of Bi2O2Se on SiO2. The field-effect-transitor device showed n-type semiconducting material with high current on/off ratio (∼108) and field-effect mobility of ∼70 cm2 V–1 s–1 which is comparable to those of traditional transition metal dichalcogenides. Technologically, the transfer-free growth of Bi2O2Se will generate high-quality hybrid material on SiO2, which can play a crucial role in highly efficient electronics.