Kim TaeWan, Kim DongHwan, Choi Chan Ho, Joung DaeHwa, Park JongHoo, Shin Jae Cheol, Kang Sang-Woo
Advanced Instrumentation Institute, Korea Research Institute of Standards and Science, Daejeon, 34113, South Korea.
Department of Physics, Yeungnam University, Gyeongsan, 38541, South Korea.
Sci Rep. 2018 Apr 27;8(1):6648. doi: 10.1038/s41598-018-25045-z.
Two-dimensional (2D) materials beyond graphene have attracted considerable interest because of the zero bandgap drawbacks of graphene. Transition metal dichalcogenides (TMDs), such as MoS and WSe, are the potential candidates for next 2D materials because atomically thin layers of TMDs exhibit unique and versatile electrical and optical properties. Although bulk TMDs materials have an indirect bandgap, an indirect-to-direct bandgap transition is observed in monolayers of TMDs (MoS, WSe, and MoSe). Optical properties of TMD films can be improved by the introduction of structural defects. For example, large-area spatial tuning of the optical transition of bulk MoS films is achieved by using an anodic aluminum oxide (AAO) template to induce structural defects such as edge- and terrace-terminated defects in a nanomesh structure. Strong photoluminescence emission peaks with a band gap of 1.81 eV are observed, possibly because of radiative transition at the defect sites. This work shows that the AAO template lithography method has potential for the production of homogenous large-scale nanomesh structures for practical semiconductor processing applications in future MoS-based electronic and optical devices.
除石墨烯之外的二维（2D）材料因石墨烯的零带隙缺陷而备受关注。过渡金属二硫属化物（TMDs），如MoS和WSe，是下一代二维材料的潜在候选者，因为原子级薄的TMDs层展现出独特且多样的电学和光学性质。尽管块状TMDs材料具有间接带隙，但在TMDs（MoS、WSe和MoSe）的单层中观察到了从间接带隙到直接带隙的转变。通过引入结构缺陷可以改善TMD薄膜的光学性质。例如，通过使用阳极氧化铝（AAO）模板在纳米网结构中诱导诸如边缘和台阶终止缺陷等结构缺陷，实现了块状MoS薄膜光学跃迁的大面积空间调控。观察到了带隙为1.81 eV的强光致发光发射峰，这可能是由于缺陷位点处的辐射跃迁所致。这项工作表明，AAO模板光刻方法在未来基于MoS的电子和光学器件的实际半导体加工应用中，具有生产均匀大规模纳米网结构的潜力。
