Low Temperature Synthesis of 2D p‐Type α‐In2Te3 with Fast and Broadband Photodetection

Abstract

Abstract2D compounds (A = Al, Ga, In, and B = S, Se, and Te) with intrinsic structural defects offer significant opportunities for high‐performance and functional devices. However, obtaining 2D atomic‐thin nanoplates with non‐layered structure on SiO2/Si substrate at low temperatures is rare, which hinders the study of their properties and applications at atomic‐thin thickness limits. In this study, the synthesis of ultrathin, non‐layered α‐In2Te3 nanoplates is demonstrated using a BiOCl‐assisted chemical vapor deposition method at a temperature below 350 °C on SiO2/Si substrate. Comprehensive characterization results confirm the high‐quality single crystal is the low‐temperature cubic phase α‐In2Te3 , possessing a noncentrosymmetric defected ZnS structure with good second harmonic generation. Moreover, α‐In2Te3 is revealed to be a p‐type semiconductor with a direct and narrow bandgap value of 0.76 eV. The field effect transistor exhibits a high mobility of 18 cm2 V−1 s−1, and the photodetector demonstrates stable photoswitching behavior within a broadband photoresponse from 405 to 1064 nm, with a satisfactory response time of τrise = 1 ms. Notably, the α‐In2Te3 nanoplates exhibit good stability against ambient environments. Together, these findings establish α‐In2Te3 nanoplates as promising candidates for next‐generation high‐performance photonics and electronics.