Low Residual Carrier Concentration and High Mobility in 2D Semiconducting Bi2O2Se

The air-stable and high-mobility two-dimensional (2D) Bi2O2Se semiconductor has emerged as a promising alternative that is complementary to graphene, MoS2, and black phosphorus for next-generation digital applications. However, the room-temperature residual charge carrier concentration of 2D Bi2O2Se nanoplates synthesized so far is as high as about 10(19)-10(20) cm(-3), which results in a poor electrostatic gate control and unsuitable threshold voltage, detrimental to the fabrication of 0 high-performance low-power devices. Here, we first present a facile approach for synthesizing 2D Bi2O2Se single crystals with ultralow carrier concentration of similar to 10(16) cm(-3) and high Hall mobility up to 410 cm(2) V-1 s(-1) simultaneously at room temperature. With optimized conditions, these high-mobility and low-carrier-concentration 2D Bi2O2Se nanoplates with domain sizes greater than 250 m and thicknesses down to 4 layers (similar to 2.5 nm) were readily grown by using Se and Bi2O3 powders as coevaporation sources in a dual heating zone chemical vapor deposition (CVD) system. High-quality 2D Bi2O2Se crystals were fabricated into high-performance and low-power transistors, showing excellent current modulation of >10(6), robust current saturation, and low threshold voltage of -0.4 V. All these features suggest 2D Bi2O2Se as an alternative option for high-performance low-power digital applications.