Defect physics and intrinsic p-type conductivity in topological insulator autls₂

Using first-principles calculations, we systematically investigate the defect physics in topological insulator AuTlS₂. An optimal growth condition is explicitly proposed to guide for the experimental synthesis. The stabilities of various native point defects under different growth conditions and different carrier environments are studied in detail. We show that the p-type conductivity is strongly preferred in AuTlS₂, and the band gap can be engineered by the control of intrinsic defects. Our results demonstrate that AuTlS₂ is an ideal p-type topological insulator which can be easily integrated with traditional semiconductor.