Exploring Native Atomic Defects in NiTe2

TL;DR

This study systematically investigates native atomic defects in NiTe2 using microscopy and calculations, revealing defect types, their dependence on growth conditions, and their influence on electronic properties.

Contribution

It provides a comprehensive analysis of native defects in NiTe2 and demonstrates how synthesis conditions can control defect types and electronic doping.

Findings

Identified five main types of native defects in NiTe2.

Growth conditions influence the type of native defects.

Native defects can slightly dope the topological surface states.

Abstract

Nickel ditelluride (NiTe2), a new discovered type-II Dirac semimetal whose Dirac node lies close to its Fermi level, is expected to exhibit exotic phenomena including Lifshitz transition and superconductivity. As we know, defects are inevitable for transition metal dichalcogenides and have significant impacts on the optical and electronic properties. However, the systematic study of defects in NiTe2 is still lack. Here, by using high-resolution scanning tunneling microscopy combined with first-principles calculations, the point defects including the vacancy, intercalation and antisite defects in NiTe2 are systematically investigated. We identified five main types native defects and revealed that the growth condition could affect the type of native defects. By controlling the ratio of ingredient during synthesis, the types of point defects are expected to be manipulated, especially antisite defects. Additionally, we find native defects could slightly dope the topological surface states. Our results provide a facile way to manipulate defects for future optimizing the electronic properties of NiTe2 and other related materials.