Gas Doping on the Topological Insulator Bi2Se3 Surface

Abstract

Gas molecule doping on the topological insulator Bi2 Se3 surface with existing Se vacancies is investigated using first-principles calculations. Consistent with experiments, NO2 and O2 are found to occupy the Se vacancy sites, remove vacancy-doped electrons and restore the band structure of a perfect surface. In contrast, NO and H2 do not favour passivation of such vacancies. Interestingly we have revealed a NO2 dissociation process that can well explain the speculative introduced "photon-doping" effect reported by recent experiments. Experimental strategies to validate this mechanism are presented. The choice and the effect of different passivators are discussed. This step paves the way for the usage of such materials in device applications utilizing robust topological surface states.

References in corpus (8)

• Topological Insulators
• Topological insulators and superconductors
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Discovery (theoretical prediction and experimental observation) of a large-gap topological-insulator class with spin-polarized single-Dirac-cone on the surface
• First observation of Spin-Momentum Helical Locking in Bi2Se3 and Bi2Te3, demonstration of Topological-Order at 300K and a realization of topological-transport-regime
• The quantum spin Hall effect and topological insulators
• Metal to insulator transition in epitaxial graphene induced by molecular doping
• Nonlinear optical probe of tunable surface electrons on a topological insulator

Cited by in corpus (12)

• Colloquium: Topological Band Theory
• Topological Surface Transport in Epitaxial SnTe Thin Films Grown on Bi2Te3
• Direct observation of band bending in topological insulator Bi2Se3
• Topological surface states of Bi2Se3 with the coexistence of Se vacancies
• Observation of Chiral Surface Excitons in a Topological Insulator Bi${}_2$Se${}_3$
• Simultaneous Magnetic and Charge Doping of Topological Insulators with Carbon
• Carrier doping of Bi${}_2$Se${}_3$ surface by chemical adsorption -- a DFT study
• Spatial Control of Charge Doping in n-Type Topological Insulators
• Micro-metric electronic patterning of a topological band structure using a photon beam
• Aggregation of BiTe Monolayer on Bi${}_2$Te${}_3$(111) Induced by Diffusion of Intercalated Atoms in van der Waals Gap
• Environmental Doping-Induced Degradation of the Quantum Anomalous Hall Insulators
• Halogen adsorption and reaction with Bi${}_2$(Se,Te)${}_3$ and Bi/Bi${}_2$(Se,Te)${}_3$