Key Laboratory of Standardization and Measurement for Nanotechnology of Chinese Academy of Sciences, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China.
ACS Nano. 2013 May 28;7(5):4610-6. doi: 10.1021/nn401420h. Epub 2013 Apr 25.
Band gap engineering of atomically thin two-dimensional (2D) materials is the key to their applications in nanoelectronics, optoelectronics, and photonics. Here, for the first time, we demonstrate that in the 2D system, by alloying two materials with different band gaps (MoS2 and WS2), tunable band gap can be obtained in the 2D alloys (Mo(1-x)W(x)S(2) monolayers, x = 0-1). Atomic-resolution scanning transmission electron microscopy has revealed random arrangement of Mo and W atoms in the Mo(1-x)W(x)S(2) monolayer alloys. Photoluminescence characterization has shown tunable band gap emission continuously tuned from 1.82 eV (reached at x = 0.20) to 1.99 eV (reached at x = 1). Further, density functional theory calculations have been carried out to understand the composition-dependent electronic structures of Mo(1-x)W(x)S(2) monolayer alloys.
原子层厚二维（2D）材料的能带工程是将其应用于纳电子学、光电学和光子学的关键。在这里，我们首次证明，在 2D 体系中，通过将两种带隙不同的材料（MoS2 和 WS2）合金化，可以在 2D 合金（Mo(1-x)W(x)S(2) 单层，x = 0-1）中获得可调谐的带隙。原子分辨率扫描透射电子显微镜揭示了 Mo(1-x)W(x)S(2) 单层合金中 Mo 和 W 原子的随机排列。光致发光特性表明，带隙发射可以连续调谐，从 1.82eV（在 x = 0.20 时达到）调谐至 1.99eV（在 x = 1 时达到）。此外，还进行了密度泛函理论计算，以理解 Mo(1-x)W(x)S(2) 单层合金的成分依赖性电子结构。
