Experimental observation of quantum confinement in the conduction band of CdSe quantum dots.
X-ray absorption spectroscopy has been used to characterize the evolution in the conduction band (CB) density of states of CdSe quantum dots (QDs) as a function of particle size. We have unambiguously witnessed the CdSe QD CB minimum (CBM) shift to higher energy with decreasing particle size, consistent with quantum confinement effects, and have directly compared our results with recent theoretical calculations. At the smallest particle size, evidence for a pinning of the CBM is presented. Our observations can be explained by considering a size-dependent change in the angular-momentum-resolved states at the CBM.
Lee
Jonathan R I
JR
Lawrence Livermore National Laboratory, Livermore, California 94550, USA. lee204@llnl.gov
Meulenberg
Robert W
RW
Hanif
Khalid M
KM
Mattoussi
Hedi
H
Klepeis
John E
JE
Terminello
Louis J
LJ
van Buuren
Tony
T