2D Lateral Heterojunction Arrays with Tailored Interface Band Bending

Abstract

AbstractTwo‐dimensional (2D) lateral heterojunction arrays, characterized by well‐defined electronic interfaces, hold significant promise for advancing next‐generation electronic devices. Despite this potential, the efficient synthesis of high‐density lateral heterojunctions with tunable interfacial band alignment remains a challenging. Here, a novel strategy is reported for the fabrication of lateral heterojunction arrays between monolayer Si2Te2 grown on Sb2Te3 (ML‐Si2Te2@Sb2Te3) and one‐quintuple‐layer Sb2Te3 grown on monolayer Si2Te2 (1QL‐Sb2Te3@ML‐Si2Te2) on a p‐doped Sb2Te3 substrate. The site‐specific formation of numerous periodically arranged 2D ML‐Si2Te2@Sb2Te3/1QL‐Sb2Te3@ML‐Si2Te2 lateral heterojunctions is realized solely through three epitaxial growth steps of thick‐Sb2Te3, ML‐Si2Te2, and 1QL‐Sb2Te3 films, sequentially. More importantly, the precisely engineering of the interfacial band alignment is realized, by manipulating the substrate's p‐doping effect with lateral spatial dependency, on each ML‐Si2Te2@Sb2Te3/1QL‐Sb2Te3@ML‐Si2Te2 junction. Atomically sharp interfaces of the junctions with continuous lattices are observed by scanning tunneling microscopy. Scanning tunneling spectroscopy measurements directly reveal the tailored type‐II band bending at the interface. This reported strategy opens avenues for advancing lateral epitaxy technology, facilitating practical applications of 2D in‐plane heterojunctions.