二硫化钨薄膜双共振上转换荧光增强研究  

Double resonance up-conversion fluorescence enhancement of tungsten disulfide films

作　　者：洪慧慧 叶佐东 HONG Huihui;Cho-Tung Yip(School of Science,Harbin Institute of Technology,Shenzhen 518055,China)

机构地区：[1]哈尔滨工业大学(深圳)理学院,广东深圳518055

出　　处：《量子电子学报》2022年第4期605-612,共8页Chinese Journal of Quantum Electronics

基　　金：深圳市科技计划项目(JCYJ20180306171818204,JCYJ20200109113003946)。

摘　　要：为探究二维层状过渡金属硫化物的激子效应,尤其是上转换过程,以层状WS_(2)样品为例开展了研究。利用532 nm连续激光和显微拉曼技术,探究了WS_(2)晶体中X 0、X−激子态物理起源和基本物理性质。利用633 nm连续激光,实现了WS_(2)晶体的单光子上转换荧光增强,证实了其背后的双共振物理机制,即入射光与X−激子态共振,在光学声子A_(1g)、E_(2g)^(1)的辅助下跃迁至高能级X 0激子态,最后自发辐射上转换荧光。此外,进一步对双共振上转换荧光的影响因素进行了分析,包括曝光时间、温度和激发功率。拟合结果表明适当增加曝光时间、减小环境温度和增加激发功率,WS_(2)的上转换荧光效率会得到提升。In order to explore the exciton effect of two-dimensional layered transition metal sulfide,especially the up-conversion fluorescence process,the layered WS2 sample was taken as an example to study.Using 532 nm continuous laser and micro-Raman technology,the physical origin and basic properties of X0 and X−exciton of WS_(2) crystal were investigated.The continuous laser of 633 nm was used to realize single photon up-conversion fluorescence enhancement,which confirmed the physical mechanism of double resonance,that is,the incident light resonates with the X−exciton state,then exciton transitions to the high-energy X0 exciton state with the aid of optical phonons A_(1g) and E_(2g)^(1),and finally produces spontaneous up-conversion fluorescence.In addition,the influencing factors of X0 were further analyzed including exposure time,temperature and excitation power.The fitting results showed that the up-conversion fluorescence efficiency could be improved by appropriately increasing the exposure time,decreasing the ambient temperature and increasing the excitation power.

关 键 词：激光物理 上转换荧光增强 双共振拉曼散射效应 二硫化钨 

分 类 号：O437[机械工程—光学工程]