Zhang Wei, Chai Changchun, Fan Qingyang, Sun Minglei, Song Yanxing, Yang Yintang, Schwingenschlögl Udo
School of Microelectronics, Xidian University, Xi'an 710071, China.
College of Information and Control Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
ACS Appl Mater Interfaces. 2021 Mar 31;13(12):14489-14496. doi: 10.1021/acsami.0c23017. Epub 2021 Mar 19.
Based on first-principles calculations, we propose a novel two-dimensional (2D) germanium carbide, tetrahex-GeC, 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-GeC 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 × 10 cm/(V s)), about 80 times that of monolayer black phosphorus. The optical absorption coefficient is ∼10 cm 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 ). Tetrahex-GeC turns out to be a very promising semiconductor for nanoelectronic, optoelectronic, and photovoltaic applications.
基于第一性原理计算，我们提出了一种新型二维碳化锗（tetrahex-GeC），并确定了其电子和光学性质。与已知的二维六方碳化锗不同，每个锗原子与四个碳原子结合。单层tetrahex-GeC具有0.89 eV的窄直接带隙，可通过施加应变和增加厚度来有效调节。其电子迁移率极高（9.5×10 cm/(V s)），约为单层黑磷的80倍。在从近红外到近紫外的宽光谱范围内，光吸收系数约为10 cm，与钙钛矿太阳能电池材料相当。我们获得了高内聚能（5.50 eV/原子）、优异的稳定性以及小的电子/空穴有效质量（0.19/0.10）。结果表明，tetrahex-GeC是一种在纳米电子、光电子和光伏应用方面非常有前景的半导体。
