Plasmon-enhanced exciton emissions and Raman scattering of CVD-grown monolayer WS2 on Ag nanoprism arrays
Plasmon-enhanced exciton emissions and Raman scattering of CVD-grown monolayer WS2 on Ag nanoprism arrays
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银纳米棱柱阵列上 CVD 生长的单层 WS2 的等离激元增强激子发射和拉曼散射
DOI：
10.1016/j.apsusc.2019.144252
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发表时间：
2020
影响因子：
6.7
通讯作者：
Wang Gaofeng
中科院分区：
文献类型：
--
作者：
Yang Weihuang;Li Hua;Chen Jiajun;Yin Jun;Li Jing;Wu Yaping;Mo Bingjie;Wu Ting;Sun Baofan;Wu Zhiming;Wang Hao;Dong Linxi;Wang Gaofeng
单层过渡金属二卤代化合物(TMD)由于原子薄，光吸收较差，通常具有较弱的光发射。通过表面等离子体共振来提高其光学性质是原子薄TMD在光电子器件和光子器件中的应用研究热点。通过控制聚苯乙烯(PS)纳米球的掩模几何形状和刻蚀时间，将化学气相沉积(CVD)生长的单层WS2转移到优化的周期Ag纳米棱镜阵列上，得到了具有良好匹配共振的Ag/WS2杂化结构。成功地实现了光致发光和拉曼散射的显著增强。特别是对单层WS2的中性激子实现了更高的增强。理论计算表明，等离子体增强主要来源于局域电场的高度增强和电荷转移。本工作探索了利用低成本和易操作的纳米球光刻技术(NSL)制备具有等离子体纳米结构的TMD的激子发射和拉曼散射增强的可行性，为等离子体增强TMD传感器、发射器和光电探测器的应用铺平了道路。
Monolayer transition metal dichalcogenides (TMDs) usually have weak optical emission due to the poor light absorption as being atomically thin. Enhancing their optical properties by surface plasmon resonance is attractive for applying atomically thin TMDs in optoelectronic and photonic devices. Here, Ag/WS2hybrid structure was fabricated by transferring monolayer WS2grown via chemical vapor deposition (CVD) onto optimized periodic Ag nanoprism array with well-matched resonance by controlling the mask geometry and etching time of polystyrene (PS) nanospheres. Significant enhanced photoluminescence (PL) emission and Raman scattering were successfully achieved. Especially, the higher enhancement is realized for neutral excitons of monolayer WS2. Theoretical calculations reveal that the plasmonic enhancement mainly results from the highly enhanced local electric field and the charge transfer. This work explores the feasibility of exciton emission and Raman scattering enhancement for TMDs with plasmonic nanostructures fabricated by low-cost and easily-manipulated nanosphere lithography (NSL), which paves a way towards the applications of plasmon-enhanced TMD sensors, emitters, and photodetectors.