Spectroscopy and Spectral Analysis, Volume. 44, Issue 1, 56(2024)
Ultrafast Dynamics of CdSe/ZnS Quantum Dots and Quantum Dot-Acceptor Molecular Complexes
QDs are a new class of semiconductor light-emitting nanomaterials, which have attracted much attention due to their unique optical properties such as adjustable luminous colorand size, wide excitation spectrum, narrow emission spectrum, etc. It is the ideal material for photovoltaic device applications in which nuclear/shell QD has better optical performance than single QD. For instance, type I nuclear/shell QD solar cell devices show higher stability and conversion efficiency in quantum dot-sensitized solar cells. Nevertheless, how the interfacial process and recombination kinetics affect the performance of devices have been the focus of attention, and the lack of related cognition has hindered the further development of quantum dot photovoltaic devices. A comprehensive study on carrier dynamics of the topical CdSe/ZnS QDs and QD-acceptor (1-chloroanthraquinone (1-CAQ), anthraquinone (AQ), and methyl viologen (MV2+)) complexes are performed employing the femtosecond time-resolved transient absorption (TA) spectroscopy and quantum chemical calculations. As indicated by the spectroscopic analysis, the fastest ET and AR processes occurred in QD-MV2+ complexes, and the ET rate was positively correlated with the AR rate. In addition, the bandgap of electron acceptor molecules and the driving force were demonstrated as crucial factors affecting the rate of the ET process according to Marcuss ET theory combined with density function calculation.This study will provide new insights into the selection of electron acceptor molecules, which will be essential in improving the design of photovoltaic devices.
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BAI Xi-lin, PENG Yue, ZHANG Xue-dong, GE Jing. Ultrafast Dynamics of CdSe/ZnS Quantum Dots and Quantum Dot-Acceptor Molecular Complexes[J]. Spectroscopy and Spectral Analysis, 2024, 44(1): 56
Received: Jun. 15, 2022
Accepted: --
Published Online: Jul. 31, 2024
The Author Email: Jing GE (703366@sxnu.edu.cn)