Semiconductor Performance Optimization on Quasi-Two-Dimensional BiO(SSe) through Monotonous Alloying.

Bismuth oxychalcogenides (BiOX, where X = S, Se, Te) have garnered significant attention recently due to their high electron mobility, air stability, and excellent photoelectric properties. Therefore, precise control and optimization over the properties of these novel quasi-2D materials are crucial for practical applications. In this study, we synthesize epitaxial films of BiO(S,Se) by the monotonous alloying of sulfur (S) and selenium (Se). Our findings reveal that the lattice constants, band gaps, and electrical properties of the films vary according to the elemental composition. Further, we observed an enhanced field-effect mobility of ∼215 cm/(V s) and an on/off ratio of ∼10 in the BiO(SSe) heterostructures with a BiSeO (BSO) oxide layer. With these efforts, this work establishes a pathway toward developing novel designs for 2D BiOX materials.