Hybrid Functional Studies on Impurity-Concentration-Controlled Band Engineering of Chalcogen-Hyperdoped Silicon

Abstract

We employ the hybrid functional method to study the impurity-concentration-controlled band engineering of chalcogen-hyperdoped silicon. The variations of defect band width and distance to the conduction band with increasing impurity concentration are given, in which at very low concentration, the reasonable depths of defect states and the energy gap compared with the experiments indicate the good accuracy of hybrid functional calculations for the band structures. For S- and Se-doped silicon, the critical concentrations for the merging of defect and conduction bands are obtained. At the key concentrations related to the insulator-to-metal transition, the characteristics of band structures are discussed.