Enhancement of No2 Sensing in Sb2te2se by Vacancies

Abstract

Topological insulators (TI) are a class of materials characterized by metallic edge states protected by time reversal symmetry from local perturbations such as defects while having a bulk insulating gap. Since the topological surface states are exposed to the environment, gas sensing applications could benefit from the higher carrier mobility of the topological surface states. In this work, we study the resistance response of Sb2Te2Se towards NO2 and the effects of vacancies introduced by annealing. We found that the vacancies greatly enhance the response and inferred the significant role the vacancies play in the mechanism of NO2 adsorption in Sb2Te2Se.

Keywords: Topological insulator, vacancies, NO2 sensing, annealing