SnP2Se6: A Chiral 2D Semiconductor for High-Performance Electronics and Optoelectronics

Abstract The growth of novel van der Waals 2D compounds is a key ingredient in discovering new phenomena in quantum materials, optoelectronics, and energy conversion. Here, we report SnP2Se6, which is a van der Waals chiral (R3 space group) semiconductor with an indirect bandgap of 1.36–1.41 eV. Mechanically exfoliated SnP2Se6 flakes are integrated into high-performance field-effect transistors with electron mobility >100 cm2/Vs and an on/off ratio >106 at room temperature. The combination of high carrier mobility and polar symmetry of SnP2Se6 results in a high short-circuit photocurrent density exceeding 300 A/cm2 upon 532 nm wavelength irradiation at an intensity of 40 W/cm2. The biased SnP2Se6 phototransistors show high gain (>4 × 10^4) and fast photoresponse (< 4 μs). These superlative properties of SnP2Se6 present diverse opportunities for emerging optoelectronic and quantum technologies.