中国物理B ›› 2012, Vol. 21 ›› Issue (10): 107801-107801.doi: 10.1088/1674-1056/21/10/107801
• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇 下一篇
姚关心a b, 吕良宏b, 桂美芳c, 张先燚b, 郑贤锋b, 季学韩b, 张宏d, 崔执凤a b
Yao Guan-Xin (姚关心)a b, L¨u Liang-Hong (吕良宏)b, Gui Mei-Fang (桂美芳)c, Zhang Xian-Yi (张先燚)b, Zheng Xian-Feng (郑贤锋)b, Ji Xue-Han (季学韩)b, Zhang Hong (张宏)d, Cui Zhi-Feng (崔执凤)a b
摘要: The ultrafast carrier relaxation processes in CdTe quantum dots are investigated by femtosecond fluorescence up-conversion spectroscopy. Photo-excited hole relaxing to the edge of the forbidden gap takes a maximal time of ~ 1.6 ps with exciting at 400 nm, depending on the state of the photo-excited hole. The shallow trapped states and deep trap states in the forbidden gap are confirmed for CdTe quantum dots. In addition, Auger relaxation of trapped carriers is observed to occur with a time constant of ~ 5 ps. A schematic model of photodynamics is established based on the results of the spectroscopy studies. Our work demonstrates that femtosecond fluorescence up-conversion spectroscopy is a suitable and effective tool in studying the transportation and conversion dynamics of photon energy in a nanosystem.
中图分类号: (High resolution nonlinear optical spectroscopy)