Orbital symmetry and the optical response of single-layer monochalcogenides

Abstract

The absorption spectra of single-layer GaSe and GaTe in the hexagonal phase feature exciton peaks with distinct polarization selectivity. We investigate these distinct features from first-principle calculations using the GW-BSE formalisms. We show that the brightness of the exciton absorption peaks is tunable with the polarization of the light. Due to the symmetry of the bands under z-axis mirror symmetry, the bound exciton states selectively couple to either in-plane or out-of-plane polarization of the light. In particular, for a p-polarized light absorption experiment, the absorption peaks of the s-like excitons emerge at large angle of incidence, while the overall absorbance reduces over the rest of the spectrum.

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Cited by in corpus (9)

• Out-of-plane orientation of luminescent excitons in atomically thin indium selenide flakes
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• How strong is the Second Harmonic Generation in single-layer monochalcogenides? A response from first-principles real-time simulations
• Control of excitonic absorption by thickness variation in few-layer GaSe
• Anisotropic Electron-Hole Excitation and Large Linear Dichroism in Two-Dimensional Ferromagnet CrSBr with In-Plane Magnetization
• First-principles study on the stability and electronic structure of monolayer GaSe with trigonal-antiprismatic structure
• Quasiparticle and Excitonic Structures of Few-layer and Bulk GaSe: Interlayer Coupling, Self-energy, and Electron-hole Interaction
• Anisotropic linear and non-linear excitonic optical properties of buckled monolayer semiconductors
• Quenching of exciton recombination in strained two-dimensional monochalcogenides