Composition-tunable 2D SnSe2(1−x)S2x alloys towards efficient bandgap engineering and high performance (opto)electronics

Abstract

Efficient bandgap engineering is a significant strategy for the utilization of widely concerned two-dimensional (2D) layered materials in versatile devices such as nanoelectronics, optoelectronics, and photonics. Alloying transition-metal dichalcogenides (TMDs) with different components has been proved as a very effective way to get 2D nanostructured semiconductors with artificially designed tunable bandgaps. Here we report a systematically study of chemical vapor transport (CVT) grown SnSe_2(1−x)S_2x alloys with continuously bandgaps ranging from 1.37 eV (SnSe₂) to 2.27 eV (SnS₂). The carrier mobility of 2D SnSe_2(1−x)S_2x nanosheets can be tuned from 2.34 cm² V⁻¹ s⁻¹ (SnS₂) to 71.30 cm² V⁻¹ s⁻¹ (SnSe₂) by controlling the S composition in the alloy. Furthermore, the carrier mobility of SnSeS increase from 10.34 to 12.16 cm² V⁻¹ s⁻¹ under illumination, showing excellent optoelectronic properties. Our study suggests that SnSe_2(1−x)S_2x nanosheets is a highly qualified 2D materials for next-generation nanoelectronics and optoelectronics application.