Chaban Vitaly V, Prezhdo Victor V, Prezhdo Oleg V
†Department of Chemistry, University of Rochester, Rochester, New York 14627, United States.
‡MEMPHYS - Center for Biomembrane Physics, Odense M. 5230, Denmark.
J Phys Chem Lett. 2013 Jan 3;4(1):1-6. doi: 10.1021/jz301878y. Epub 2012 Dec 12.
Nonadiabatic molecular dynamics combined with time-domain density functional theory are used to study electron transfer (ET) from a CdSe quantum dot (QD) to the C60 fullerene, occurring in several types of hybrid organic/inorganic nanocomposites. By unveiling the time dependence of the ET process, we show that covalent bonding between the QD and C60 is particularly important to ensure ultrafast transmission of the excited electron from the QD photon-harvester to the C60 electron acceptor. Despite the close proximity of the donor and acceptor species provided by direct van der Waals contact, it leads to a notably weaker QD-C60 interaction than a lengthy molecular bridge. We show that the ET rate in a nonbonded mixture of QDs and C60 can be enhanced by doping. The photoinduced ET is promoted primarily by mid- and low-frequency vibrations. The study establishes the basic design principles for enhancing photoinduced charge separation in nanoscale light harvesting materials.
非绝热分子动力学与时域密度泛函理论相结合，用于研究在几种类型的有机/无机杂化纳米复合材料中发生的从CdSe量子点（QD）到C60富勒烯的电子转移（ET）。通过揭示ET过程的时间依赖性，我们表明QD和C60之间的共价键对于确保激发电子从QD光子捕获器超快传输到C60电子受体尤为重要。尽管通过直接范德华接触使供体和受体物种紧密接近，但它导致的QD - C60相互作用比长分子桥明显更弱。我们表明，通过掺杂可以提高QD和C60非键合混合物中的ET速率。光诱导ET主要由中低频振动促进。该研究确立了增强纳米级光捕获材料中光诱导电荷分离的基本设计原则。
