Strong Modulation of Optical Properties in Rippled 2D GaSe via Strain Engineering
arXiv:1903.02449 · doi:10.1088/1361-6528/ab0bc1
Abstract
Few-layer GaSe is one of the latest additions to the family of 2D semiconducting crystals whose properties under strain are still relatively unexplored. Here, we study rippled nanosheets that exhibit a periodic compressive and tensile strain of up to 5%. The strain profile modifies the local optoelectronic properties of the alternating compressive and tensile regions, which translates into a remarkable shift of the optical absorption band-edge of up to 1.2 eV between crests and valleys. Our experimental observations are supported by theoretical results from density functional theory calculations performed for monolayers and multilayers (up to 7 layers) under tensile and compressive strain. This large band gap tunability can be explained through a combined analysis of the elastic response of Ga atoms to strain and the symmetry of the wave functions.
Main text: 10 pages, 3 figures. Supp. Info: 10 pages, 7 figures
References in corpus (7)
- Two Dimensional Atomic Crystals
- Two-Dimensional Material Nanophotonics
- High Electron Mobility, Quantum Hall Effect and Anomalous Optical Response in Atomically Thin InSe
- Micro-reflectance and transmittance spectroscopy: a versatile and powerful tool to characterize 2D materials
- Mechanics of freely-suspended ultrathin layered materials
- Tunable Quasiparticle Band Gap in Few Layer GaSe/graphene Van der Waals Heterostructures
- Ultrasensitive Tunability of the Direct Bandgap of Two-dimensional InSe Flakes via Strain Engineering