Growth, Raman Scattering Investigation and Photodetector Properties of 2D SnP

Abstract As an important metal phosphides material, 2D tin phosphides (SnP_x 0 < x ≤ 3) have been theoretically predicted to have intriguing physicochemical properties and potential applications in electronics, optoelectronics, and energy fields. However, the synthesis of high‐quality 2D SnP single crystal has not been reported due to the lack of efficiency and reliable growth method. Here, a facile atmospheric pressure chemical vapor deposition (APCVD) method is developed to realize the growth of high‐quality 2D SnP nanosheets, by employing tin (Sn) foil as both liquid metal substrates and reaction precursor. Temperature‐dependent and angle‐resolved polarization Raman spectra observed Raman peaks located at 142.6, 303.3, and 444.2 cm^‐1 are concluded to belong to A_1g mode, which are consistent with the theoretical calculation results. Moreover, the field‐effect transistor (FET) devices based on SnP nanosheets show a typical n‐type characteristic with an on/off ratio of 10³ at 200 K. SnP nanosheets also demonstrate excellent photoresponse performance under the illumination of 473, 532, and 639 nm lasers, which can be tuned by V_gs, V_ds, and light power density. It is believed that these findings can provide the first‐hand experimental information for the future study of 2D SnP nanosheets.