Computational prediction of two-dimensional group-IV mono-chalcogenides

Arunima K. Singh, Richard G. Hennig

Research output: Contribution to journalArticle

144 Scopus citations

Abstract

Density functional calculations determine the structure, stability, and electronic properties of two-dimensional materials in the family of group-IV monochalcogenides, MX (M=Ge, Sn, Pb; X=O, S, Se, Te). Calculations with a van der Waals functional show that the two-dimensional IV-VI compounds are most stable in either a highly distorted NaCl-type structure or a single-layer litharge type tetragonal structure. Their formation energies are comparable to single-layer MoS2, indicating the ease of mechanical exfoliation from their layered bulk structures. The phonon spectra confirm their dynamical stability. Using the hybrid HSE06 functional, we find that these materials are semiconductors with bandgaps that are generally larger than for their bulk counterparts due to quantum confinement. The band edge alignments of monolayer group IV-VI materials reveal several type-I and type-II heterostructures, suited for optoelectronics and solar energy conversion.

Original languageEnglish (US)
Article number042103
JournalApplied Physics Letters
Volume105
Issue number4
DOIs
StatePublished - Jul 28 2014

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)

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