Photoluminescence inhomogeneity and excitons in CVD-grown monolayer WS2
Photoluminescence inhomogeneity and excitons in CVD-grown monolayer WS2
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CVD 生长的单层 WS2 中的光致发光不均匀性和激子
DOI：
10.1016/j.optmat.2018.04.043
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发表时间：
2018
影响因子：
3.9
通讯作者：
Xu Cheng-Yan
中科院分区：
文献类型：
--
作者：
Ren Dan-Dan;Qin Jing-Kai;Li Yang;Miao Peng;Sun Zhao-Yuan;Xu Ping;Zhen Liang;Xu Cheng-Yan
过渡金属二硫属化物二维材料对于未来的电子和光电应用具有重要意义。在这项工作中，通过化学气相沉积方法制备了尺寸达130μm的三角形WS2单层。 WS2单层呈现均匀的拉曼强度，同时在中心观察到猝灭光致发光（PL）。 WS2单层薄片中心部分的PL猝灭归因于硫空位向中心逐渐增加。 PL 光谱中负 Trion (X−) 的比例随着 WS2 中硫空位的增加而增加。 X−结合能的增强表明更高的费米能级和n掺杂水平以及更大的硫空位浓度。我们的发现可能有益于集成器件的开发，并探索纳米光子学中缺陷引起的光学和电学特性。
Transition metal dichalcogenides two-dimensional materials are of great importance for future electronic and optoelectronic applications. In this work, triangular WS2monolayers with size up to 130 μm were prepared via chemical vapor deposition method. WS2monolayers presented uniform Raman intensity, while quenched photoluminescence (PL) was observed in the center. The PL quenching in the central part of WS2monolayer flakes was attributed to the gradually increasing sulfur vacancies toward the center. The proportion of negative trion (X−) in PL spectrum increases with increasing sulfur vacancies in WS2. The enhanced binding energy of X−suggests higher Fermi level and n-doping level with larger sulfur vacancy concentration. Our findings may be beneficial to the development of integrated devices, and also explore the defect-induced optical and electrical properties for nanophotonics.