Controlling electronic and optical properties of layered SiC and GeC sheets by strain engineering

The structural, electronic, and optical properties of optimized layered SiC and GeC in a two-dimensional honeycomb structure are analyzed based on the density functional theory. The stability is testified by analysis of phonon dispersion curves. The variations of electronic and optical properties of layered SiC and GeC under in-plane and out-of-plane strain effect are also investigated. The results show that tunable band structures and optical properties of layered SiC and GeC, such as indirect-direct band gap transition, shrink and enlargement of band gaps, red and blue shift of absorption peaks, can be achieved by applying strain. These results provide new routes for tailoring the electronic and optical properties of these ultrathin nanofilms, which demonstrate new potential applications of these materials in optoelectronics and energy engineering. (C) 2016 Elsevier Ltd. All rights reserved.