First-principles study on the structural, elastic, thermodynamic and electronic properties of In-doped bulk WSe 2

The structural, mechanical, thermodynamic and electronic properties of indium (In) substitution for W and Se as well as intercalating In in bulk WSe 2 have been investigated by first-principles calculation. The dopant indium is more likely to substitute for W (or Se) under Se-rich (or W rich) conditions. Doping decreases the elastic modulus, hardness, Debye temperature and the minimum thermal conductivity of WSe 2 (e.g., InW 8 Se 16 has the lowest values) but effectively improves the ductile and lubrication property (e.g., InW 7 Se 16 and InW 8 Se 16 present a largest ductile and lubrication property, respectively). WSe 2 together with the dopant are all anisotropic. InW 8 Se 16 performs the largest degree of anisotropy among them. Indium doping cannot introduce magnetism. However, it can transform the semiconductor of pure WSe 2 to semimetal. Both of the substituted structures character the p-type doping nature while the intercalated structure characters the n-type doping nature. The hybridization of W-d and Se-p electrons are the main cause of the W–Se covalent bond. New covalent bonds are formed for the In-doped structures.