Shape dependent ultrafast relaxation dynamics of CdSe nanocrystals: Nanorods vs nanodots

被引:118
作者
Mohamed, MB [1 ]
Burda, C [1 ]
El-Sayed, MA [1 ]
机构
[1] Georgia Inst Technol, Sch Chem & Biochem, Laser Dynam Lab, Atlanta, GA 30332 USA
关键词
D O I
10.1021/nl0155835
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Femtosecond pump-probe transient spectroscopy is used to compare the time dependence of the bleach recovery of CdSe nanorods with that of nanodots. In the quantum dots the bleach spectrum evolved rapidly to its characteristic shape, while in the nanorods, the higher energy exciton states are first populated within the laser pulse width (100 fs) and then relax to lower states. This behavior is explained by the larger number of exciton states in the rods due to splitting of the degeneracy of the states in the dots as a result of the decrease in symmetry as predicted from existing theories.
引用
收藏
页码:589 / 593
页数:5
相关论文
共 47 条
[1]   ELECTRONIC STATES OF SEMICONDUCTOR CLUSTERS - HOMOGENEOUS AND INHOMOGENEOUS BROADENING OF THE OPTICAL-SPECTRUM [J].
ALIVISATOS, AP ;
HARRIS, AL ;
LEVINOS, NJ ;
STEIGERWALD, ML ;
BRUS, LE .
JOURNAL OF CHEMICAL PHYSICS, 1988, 89 (07) :4001-4011
[2]   Perspectives on the physical chemistry of semiconductor nanocrystals [J].
Alivisatos, AP .
JOURNAL OF PHYSICAL CHEMISTRY, 1996, 100 (31) :13226-13239
[3]  
Braun M, 2001, J PHYS CHEM A, V105, P5548, DOI 10.1021/jp0100021
[4]   Femtosecond time-resolved electron-hole dynamics and radiative transitions in the double-layer quantum well of the CdS/(HgS)2/CdS quantum-dot-quantum-well nanoparticle -: art. no. 035317 [J].
Braun, M ;
Burda, C ;
Mohamed, M ;
El-Sayed, M .
PHYSICAL REVIEW B, 2001, 64 (03)
[5]   ZERO-DIMENSIONAL EXCITONS IN SEMICONDUCTOR CLUSTERS [J].
BRUS, L .
IEEE JOURNAL OF QUANTUM ELECTRONICS, 1986, 22 (09) :1909-1914
[6]   QUANTUM CRYSTALLITES AND NONLINEAR OPTICS [J].
BRUS, L .
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING, 1991, 53 (06) :465-474
[10]  
BUONOCORE F, 2000, J PHYS CONDENS MATT, V112, P521