Chen Jia-Shiang, Li Mingxing, Wu Qin, Fron Eduard, Tong Xiao, Cotlet Mircea
Center for Functional Nanomaterials , Brookhaven National Laboratory , Upton , New York 11973 , United States.
Department of Materials Science and Chemical Engineering , Stony Brook University , Stony Brook , New York 11794 , United States.
ACS Nano. 2019 Jul 23;13(7):8461-8468. doi: 10.1021/acsnano.9b04367. Epub 2019 Jul 5.
We demonstrate layer-dependent electron transfer between core/shell PbS/CdS quantum dots (QDs) and layered MoS energy band gap engineering of both the donor (QDs) and the acceptor (MoS) components. We do this by (i) changing the size of the QD or (ii) by changing the number of layers of MoS, and each of these approaches alters the band gap and/or the donor-acceptor separation distance, thus providing a means of tuning the charge-transfer rate. We find the charge-transfer rate to be maximal for QDs of smallest size and for QDs combined with a 5-layer MoS or thicker. We model this layer-dependent charge-transfer rate with a theoretical model derived from Marcus theory previously applied to nonadiabatic electron transfer in weakly coupled systems by considering the QD transferring photogenerated electrons to noninteracting monolayers within a few layers of MoS.
我们展示了核壳结构的硫化铅/硫化镉量子点（QDs）与层状二硫化钼之间的层依赖电子转移，这涉及施主（量子点）和受主（二硫化钼）组件的能带隙工程。我们通过以下方式实现这一点：（i）改变量子点的尺寸，或（ii）改变二硫化钼的层数，并且这些方法中的每一种都会改变带隙和/或施主 - 受主分离距离，从而提供一种调节电荷转移速率的手段。我们发现，对于尺寸最小的量子点以及与5层或更厚的二硫化钼组合的量子点，电荷转移速率最大。我们用一个从马库斯理论推导出来的理论模型对这种层依赖电荷转移速率进行建模，该理论模型先前已应用于弱耦合系统中的非绝热电子转移，通过考虑量子点将光生电子转移到二硫化钼几层内的非相互作用单层中。
