Abstract
, a semiconductor at ambient conditions, does not exhibit an excitonic insulating state like its selenium counterpart , owing to its large band gap. Using a combination of Raman spectroscopy and analysis with first-principles effective Hamiltonian, we explore its instability toward an excitonic insulating state as a function of pressure, and affirm that excitonic insulating state does not get stabilized in with pressure. We observe pressure-induced structural phase transition from its orthorhombic structure to another orthorhombic structure, with onset at 4.2 GPa and this transition gets completed at 6 GPa. We observe Raman signatures of an additional phase transition at 10.8 GPa, which is suggested to be associated with a semiconductor to metal transition.
- Received 17 September 2023
- Revised 28 February 2024
- Accepted 26 March 2024
DOI:https://doi.org/10.1103/PhysRevB.109.155202
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