Characterization of Bi-incorporated InSb(111)A/B Surfaces : An STM and XPS Study

Abstract: In recent years, III-V semiconductor materials have received increasing attention due to their admirable electronic properties like direct tunable bandgaps and high charge carrier mobility. Indium Antimonide (InSb) possesses the largest electron mobility among III-V materials and is promising for infrared detectors, high-speed field effect transistors, and spintronics. Incorporation of bismuth (Bi) into III-V semiconductors can enhance spin-orbit coupling and reduce the band gap. To modify III-V semiconductors with the desired electronic properties and eventually allow industrial fabrication, there are a few challenges to overcome. One is to understand surface modifications. In this study, the surface properties of InSb(111)A/B with Bi incorporation are investigated with highly surface-sensitive characterization techniques of scanning tunneling microscopy (STM) and X-ray photoelectron spectroscopy (XPS). Clean InSb(111)A and InSb(111)B surfaces exhibit (2×2) and (3×3) reconstructions, respectively. After the Bi deposition, the surfaces display amorphous Bi aggregations. An Sb-Bi bonding configuration is found on the Bi-deposited surface, followed by a Bi-Bi component corresponding to a metallic Bi layer. The Bi spectra of a sequence of deposition and annealing steps are discussed.