过渡金属硫化物二维单层半导体纳米材料超快时间分辨动力学性质研究

项目名称： 过渡金属硫化物二维单层半导体纳米材料超快时间分辨动力学性质研究

项目编号： No.61308034

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 张赛锋

作者单位： 中国科学院上海光学精密机械研究所

项目金额： 26万元

中文摘要： 过渡金属硫化物二维单层材料作为层状半导体超快光电子学研究的新兴领域备受人们关注。本项目以典型过渡金属硫化物二维单层及寡层半导体材料为研究载体，采用液相剥离技术制备具有清洁度高、尺寸在微米/亚微米量级的高质量单层及寡层单体，利用超快时间分辨双色显微泵浦-探测系统、时间关联单光子计数技术、空间高分辨共焦显微光谱探测技术，分析样品层数、元素类型、基底与荧光寿命、载流子迁移率、扩散系数等的依赖关系，深入研究在温度、激发光波长、强度等外加条件调制下微纳层状半导体的光动力学性质和同族变化规律，结合理论拟合，阐明过渡金属硫系化合物超快载流子弛豫等动力学过程的物理本质。二维体系的层数、晶格完整性和材料组成直接决定其载流子动力学行为，实现单层及寡层载流子迁移率、激子寿命、载流子扩散速率等的精确测量并深入理解二维限制效应所诱发的各种新奇物理现象，对未来微平面超快光电子器件的开发应用具有非常重要的意义。

中文关键词： 过渡金属硫化物；双光子吸收；饱和吸收；光学非线性；

英文摘要： The transition metal dichalcogenides (TMDC) 2-Dimensional monolayer materials have been an emerging field in the investigation on layered ultrafast semiconductor optoelectronics and drawn much attention in recent years. The project aims at typical TMDC 2D mono- and few-layer semiconductor materials, in combination with liquid exfoliation technique for high cleanliness and high quality micro or sub-micro sized sample, ultrafast time-resolved two color beam micro pump-probe system, time correlated single photon counting technique, high spatial resolution confocal micro spectra detection technique, to analyze the relationship between layer number, element type, substrate and photoluminescence lifetime, carrier mobility, diffusion coefficient, etc. and thoroughly study the photo induced dynamics properties and find the congener characteristics under external modulations such as temperature, the excitation wavelength and intensity. Supported by theoretical simulation, the physical mechanisms of dynamics like ultrafast carrier relaxation in TMDCs are expected to be clearly clarified. The carrier dynamics depends directly on the layer number, the perfection of lattice and the composition of the material. It is significant to realize precise measurement of carrier mobility, the lifetime of exciton, the diffusion rate, e

英文关键词： transition metal dichalcogenides；two-photo absorption；saturable absorption；nonlinear optics；