TY - JOUR
T1 - Temporary Charge Carrier Separation Dominates the Photoluminescence Decay Dynamics of Colloidal CdSe Nanoplatelets
AU - Rabouw, F.T.
AU - van der Bok, J.C.
AU - Spinicelli, Piernicola
AU - Mahler, B.
AU - Nasilowski, M.
AU - Pedetti, S.
AU - Dubertret, B.
AU - Vanmaekelbergh, Daniel
PY - 2016
Y1 - 2016
N2 - Luminescent colloidal CdSe nanoplatelets with atomically defined thicknesses have recently been developed, and their potential for various applications has been shown. To understand their special properties, experiments have until now focused on the relatively short time scales of at most a few nanoseconds. Here, we measure the photoluminescence decay dynamics of colloidal nanoplatelets on time scales up to tens of microseconds. The excited state dynamics are found to be dominated by the slow (∼μs) dynamics of temporary exciton storage in a charge-separated state, previously overlooked. We study the processes of charge carrier separation and exciton recovery in pure CdSe nanoplatelets as well as in core–crown and core–shell CdSe/CdS nanoplatelets with high ensemble quantum yields of 50%, and discuss the implications. Our work highlights the importance of reversible charge carrier trapping and experiments over a wide range of time scales for the understanding of colloidal nanoemitters in general and nanoplatelets in particular.
AB - Luminescent colloidal CdSe nanoplatelets with atomically defined thicknesses have recently been developed, and their potential for various applications has been shown. To understand their special properties, experiments have until now focused on the relatively short time scales of at most a few nanoseconds. Here, we measure the photoluminescence decay dynamics of colloidal nanoplatelets on time scales up to tens of microseconds. The excited state dynamics are found to be dominated by the slow (∼μs) dynamics of temporary exciton storage in a charge-separated state, previously overlooked. We study the processes of charge carrier separation and exciton recovery in pure CdSe nanoplatelets as well as in core–crown and core–shell CdSe/CdS nanoplatelets with high ensemble quantum yields of 50%, and discuss the implications. Our work highlights the importance of reversible charge carrier trapping and experiments over a wide range of time scales for the understanding of colloidal nanoemitters in general and nanoplatelets in particular.
KW - Colloidal nanoplatelets
KW - photoluminescence decay
KW - exciton recombination
KW - charge carrier trapping
U2 - 10.1021/acs.nanolett.6b00053
DO - 10.1021/acs.nanolett.6b00053
M3 - Article
SN - 1530-6984
VL - 16
SP - 2047
EP - 2053
JO - Nano Letters
JF - Nano Letters
ER -