In situ optical and structural studies on photoluminesence quenching in CdSe/CdS/Au heterostructures.
We report here detailed in situ studies of nucleation and growth of Au on CdSe/CdS nanorods using synchrotron SAXS technique and time-resolved spectroscopy. We examine structural and optical properties of CdSe/CdS/Au heterostructures formed under UV illumination. We compare the results for CdSe/CdS/Au heterostructures with the results of control experiments on CdSe/CdS nanorods exposed to gold precursor under conditions when no such heterostructures are formed (no UV illumination). Our data indicate similar photoluminescence (PL) quenching and PL decay profiles in both types of samples. Via transient absorption and PL, we show that such behavior is consistent with rapid (faster than 3 ps) hole trapping by gold-sulfur sites at the surface of semiconductor nanoparticles. This dominant process was overlooked in previous end-point studies on semiconductor/metal heterostructures.
Center for Nanoscale Materials, ‡Materials Science Division, §Advanced Photon Source, ∥Chemical Sciences and Engineering Division, ⊥Electron Microscopy Center, Argonne National Laboratory, 9700 South Cass Ave., Argonne, Illinois 60439, United States.
Arnaud
A
Demortière
Richard D
RD
Schaller
Tao
T
Li
Soma
S
Chattopadhyay
Galyna
G
Krylova
Tomohiro
T
Shibata
Paula C
PC
dos Santos Claro
Clare E
CE
Rowland
Jeffrey T
JT
Miller
Russell
R
Cook
Byeongdu
B
Lee
Elena V
EV
Shevchenko