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

Abstract

Abstract 2D 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 SiO 2 /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 ‐In 2 Te 3 nanoplates is demonstrated using a BiOCl‐assisted chemical vapor deposition method at a temperature below 350 °C on SiO 2 /Si substrate. Comprehensive characterization results confirm the high‐quality single crystal is the low‐temperature cubic phase α ‐In 2 Te 3 , possessing a noncentrosymmetric defected ZnS structure with good second harmonic generation. Moreover, α‐ In 2 Te 3 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 cm 2 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 τ rise = 1 ms. Notably, the α‐ In 2 Te 3 nanoplates exhibit good stability against ambient environments. Together, these findings establish α ‐In 2 Te 3 nanoplates as promising candidates for next‐generation high‐performance photonics and electronics.