Zeng Hui, Zhao Jun, Cheng Ai-Qiang, Zhang Lei, He Zi, Chen Ru-Shan
School of Electronic and Optical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, People's Republic of China.
Nanotechnology. 2018 Feb 16;29(7):075201. doi: 10.1088/1361-6528/aaa2e8.
Searching for new van der Waals (vdW) heterostructure with novel electronic and optical properties is of great interest and importance for the next generation of devices. By using first-principles calculations, we show that the electronic and optical properties of the arsenene/CN vdW heterostructure can be effectively modulated by applying vertical strain and external electric field. Our results suggest that this heterostructure has an intrinsic type-II band alignment with an indirect bandgap of 0.16 eV, facilitating the separation of photogenerated electron-hole pairs. The bandgap in the heterostructure can be tuned from 0-0.35 eV via the strain, experiencing an indirect-to-direct bandgap transition. Moreover, the bandgap of the heterostructure varies linearly with respect to a moderate external electric field, and the semiconductor-to-metal transition can be realized in the presence of a strong electric field. The calculated band alignment and the optical absorption reveal that the arsenene/CN heterostructure could present excellent light-harvesting performance. Our designed vdW heterostructure is expected to have great potential applications in nanoelectronic devices and photovoltaics.
寻找具有新颖电子和光学特性的新型范德华（vdW）异质结构对于下一代器件具有极大的吸引力和重要性。通过第一性原理计算，我们表明，施加垂直应变和外部电场可以有效地调制砷烯/碳氮化物vdW异质结构的电子和光学特性。我们的结果表明，这种异质结构具有本征II型能带排列，间接带隙为0.16 eV，有利于光生电子 - 空穴对的分离。通过应变，异质结构中的带隙可以在0 - 0.35 eV之间调节，经历间接到直接的带隙转变。此外，异质结构的带隙相对于适度的外部电场呈线性变化，并且在强电场存在下可以实现半导体到金属的转变。计算得到的能带排列和光吸收表明，砷烯/碳氮化物异质结构可以呈现出优异的光捕获性能。我们设计的vdW异质结构有望在纳米电子器件和光伏领域具有巨大的潜在应用。
