Salt-Assisted Low-Temperature Growth of 2D Bi2O2Se with Controlled Thickness for Electronics

Bi2O2Se is the most promising 2D material due to its semiconducting feature and high mobility, making it propitious channel material for high-performance electronics that demands highly crystalline Bi2O2Se at low-growth temperature. Here, a low-temperature salt-assisted chemical vapor deposition approach for growing single-domain Bi2O2Se on a millimeter scale with thicknesses of multilayer to monolayer is presented. Because of the advantage of thickness-dependent growth, systematical scrutiny of layer-dependent Raman spectroscopy of Bi2O2Se from monolayer to bulk is investigated, revealing a redshift of the A(1g) mode at 162.4 cm(-1). Moreover, the long-term environmental stability of approximate to 2.4 nm thick Bi2O2Se is confirmed after exposing the sample for 1.5 years to air. The backgated field effect transistor (FET) based on a few-layered Bi2O2Se flake represents decent carrier mobility (approximate to 287 cm(2) V(-1)s(-1)) and an ON/OFF ratio of up to 10(7). This report indicates a technique to grow large-domain thickness controlled Bi2O2Se single crystals for electronics.

Automated summary

A low-temperature salt-assisted chemical vapor deposition method was used to grow single-domain Bi2O2Se on a millimeter scale with multilayer to monolayer thickness. The layer-dependent Raman spectroscopy of Bi2O2Se was systematically investigated, showing a redshift of the A(1g) mode at 162.4 cm(-1). The environmental stability of approximately 2.4 nm thick Bi2O2Se was confirmed after exposure to air for 1.5 years. The backgated field effect transistor based on a few-layered Bi2O2Se exhibited decent carrier mobility (approximately 287 cm(2) V(-1)s(-1)) and an ON/OFF ratio of up to 10(7), indicating a technique for growing large-domain thickness controlled Bi2O2Se single crystals for electronics.