Semiconductor-metal transition in semiconducting bilayer sheets of transition metal dichalcogenides

By S. Bhattacharyya, Abhishek K. Singh. 2012

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Using first-principles calculations we show that the band gap of bilayer sheets of semiconducting transition-metal dichalcogenides (TMDs) can be reduced smoothly by applying vertical compressive pressure. These materials undergo a universal reversible semiconductor-to-metal (S-M) transition at a critical pressure. The S-M transition is attributed to lifting of the degeneracy of the bands at the Fermi level caused by interlayer interactions via charge transfer from the metal to the chalcogen. The S-M transition can be reproduced even after incorporating the band gap corrections using hybrid functionals and the GW method. The ability to tune the band gap of TMDs in a controlled fashion over a wide range of energy opens up the possibility for its usage in a range of applications.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/4fc80a5c5c76e31a7ece2f619ef40dfd4fd08049