Doping stability and charge-density-wave transition of strained 1T-TiSe ₂

Abstract

Through a series of first-principles calculations, we reveal the doping stabilities of strained TiSe2 in both normal and charge density wave (CDW) states. Two critical carrier concentrations are revealed for both electron and hole dopings. The first one corresponds to the situation when CDW transition is totally eliminated after charge doping, while the second one corresponds to the situation when TiSe2 becomes structurally unstable due to charge doping. We systematically investigate and quantitatively reveal the modulations on these two critical doping concentrations by biaxial strains. Our study serves as an important supplement to understanding phase transitions of TiSe2, especially where charge doping or external strains are applied.