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Structural evolution and phase transition mechanism of [Formula: see text] under high pressure.

Journal Article


Abstract


  • [Formula: see text] is a layered transition-metal dichalcogenide (TMD) with outstanding electronic and optical properties, which is widely used in field-effect transistor (FET). Here the structural evolution and phase transition of [Formula: see text] under high pressure are systematically studied by CALYPSO structural search method and first-principles calculations. The structural evolutions of [Formula: see text] show that the ground state structure under ambient pressure is the experimentally observed P6[Formula: see text]/mmc phase, which transfers to R3m phase at 1.9 GPa. The trigonal R3m phase of [Formula: see text] is stable up to 72.1 GPa, then, it transforms into a new P6[Formula: see text]/mmc phase with different atomic coordinates of Se atoms. This phase is extremely robust under ultrahigh pressure and finally changes to another trigonal R-3m phase under 491.1 GPa. The elastic constants and phonon dispersion curves indicate that the ambient pressure phase and three new high-pressure phases are all stable. The electronic band structure and projected density of states analyses reveal a pressure induced semiconducting to metallic transition under 72.1 GPa. These results offer a detailed structural evolution and phase diagram of [Formula: see text] under high pressure, which may also provide insights for exploration other TMDs under ultrahigh pressure.

Publication Date


  • 2021

Citation


  • Xiao, Y., He, S., Li, M., Sun, W., Wu, Z., Dai, W., & Lu, C. (2021). Structural evolution and phase transition mechanism of [Formula: see text] under high pressure.. Scientific reports, 11(1), 22090. doi:10.1038/s41598-021-01527-5

Web Of Science Accession Number


Start Page


  • 22090

Volume


  • 11

Issue


  • 1

Abstract


  • [Formula: see text] is a layered transition-metal dichalcogenide (TMD) with outstanding electronic and optical properties, which is widely used in field-effect transistor (FET). Here the structural evolution and phase transition of [Formula: see text] under high pressure are systematically studied by CALYPSO structural search method and first-principles calculations. The structural evolutions of [Formula: see text] show that the ground state structure under ambient pressure is the experimentally observed P6[Formula: see text]/mmc phase, which transfers to R3m phase at 1.9 GPa. The trigonal R3m phase of [Formula: see text] is stable up to 72.1 GPa, then, it transforms into a new P6[Formula: see text]/mmc phase with different atomic coordinates of Se atoms. This phase is extremely robust under ultrahigh pressure and finally changes to another trigonal R-3m phase under 491.1 GPa. The elastic constants and phonon dispersion curves indicate that the ambient pressure phase and three new high-pressure phases are all stable. The electronic band structure and projected density of states analyses reveal a pressure induced semiconducting to metallic transition under 72.1 GPa. These results offer a detailed structural evolution and phase diagram of [Formula: see text] under high pressure, which may also provide insights for exploration other TMDs under ultrahigh pressure.

Publication Date


  • 2021

Citation


  • Xiao, Y., He, S., Li, M., Sun, W., Wu, Z., Dai, W., & Lu, C. (2021). Structural evolution and phase transition mechanism of [Formula: see text] under high pressure.. Scientific reports, 11(1), 22090. doi:10.1038/s41598-021-01527-5

Web Of Science Accession Number


Start Page


  • 22090

Volume


  • 11

Issue


  • 1