Effect of Thermal Fluctuations on the Radiative Rate in Core/Shell Quantum Dots.
The effect of lattice fluctuations and electronic excitations on the radiative rate is demonstrated in CdSe/CdS core/shell spherical quantum dots (QDs). Using a combination of time-resolved photoluminescence spectroscopy and atomistic simulations, we show that lattice fluctuations can change the radiative rate over the temperature range from 78 to 300 K. We posit that the presence of the core/shell interface plays a significant role in dictating this behavior. We show that the other major factor that underpins the change in radiative rate with temperature is the presence of higher energy states corresponding to electron excitation into the shell. These effects should be present in other core/shell samples and should also affect other excited state rates, such as the rate of Auger recombination or the rate of charge transfer.
Department of Chemistry, University of California, Berkeley , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|Kavli Energy NanoScience Institute , Berkeley, California 94720, United States.
Arunima D
0000-0002-9216-7806
AD
Balan
Hagai
H
Eshet
Department of Chemistry, University of California, Berkeley , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|Kavli Energy NanoScience Institute , Berkeley, California 94720, United States.
Jacob H
0000-0003-3658-1487
JH
Olshansky
Department of Chemistry, University of California, Berkeley , Berkeley, California 94720, United States.
Youjin V
YV
Lee
Department of Chemistry, University of California, Berkeley , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
Eran
E
Rabani
Department of Chemistry, University of California, Berkeley , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|Kavli Energy NanoScience Institute , Berkeley, California 94720, United States.|Department of Materials Science and Engineering, University of California , Berkeley, California 94720, United States.
A Paul
0000-0001-6895-9048
AP
Alivisatos
Core/shell quantum dots; electronic structure; exciton dynamics; temperature-dependent lifetime