Based on first-principles calculations, we propose a novel two-dimensional (2D) germanium carbide, tetrahex-GeC2, and determine its electronic and optical properties. Each Ge atom binds to four C atoms, in contrast to the known 2D hexagonal germanium carbides. Monolayer tetrahex-GeC2 possesses a narrow direct band gap of 0.89 eV, which can be effectively tuned by applying strain and increasing the thickness. Its electron mobility is extraordinarily high (9.5 × 104 cm2/(V s)), about 80 times that of monolayer black phosphorus. The optical absorption coefficient is ∼106 cm-1 in a wide spectral range from near-infrared to near-ultraviolet, comparable to perovskite solar cell materials. We obtain high cohesive energy (5.50 eV/atom), excellent stability, and small electron/hole effective mass (0.19/0.10 m0). Tetrahex-GeC2 turns out to be a very promising semiconductor for nanoelectronic, optoelectronic, and photovoltaic applications.
|Original language||English (US)|
|Journal||ACS Applied Materials & Interfaces|
|State||Published - Mar 19 2021|
Bibliographical noteKAUST Repository Item: Exported on 2021-03-22
Acknowledgements: The authors acknowledge generous financial support from the National Natural Science Foundation of China (Nos. 61974116 and 61804120), the China Postdoctoral Science Foundation (Nos. 2019TQ0243 and 2019M663646), and the Key Scientific Research Project of Education Department of Shaanxi-Key Laboratory Project (No. 20JS066). The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). We acknowledge Xidian University and KAUST for computational resources and support.
ASJC Scopus subject areas
- Materials Science(all)