Peterson Mark D, Cass Laura C, Harris Rachel D, Edme Kedy, Sung Kimberly, Weiss Emily A
Department of Chemistry, Northwestern University, Evanston, Illinois 60208-3113; email:
Annu Rev Phys Chem. 2014;65:317-39. doi: 10.1146/annurev-physchem-040513-103649. Epub 2013 Dec 20.
This article reviews the mechanisms through which molecules adsorbed to the surfaces of semiconductor nanocrystals, quantum dots (QDs), influence the pathways for and dynamics of intra- and interband exciton relaxation in these nanostructures. In many cases, the surface chemistry of the QDs determines the competition between Auger relaxation and electronic-to-vibrational energy transfer in the intraband cooling of hot carriers, and between electron or hole-trapping processes and radiative recombination in relaxation of band-edge excitons. The latter competition determines the photoluminescence quantum yield of the nanocrystals, which is predictable through a set of mostly phenomenological models that link the surface coverage of ligands with specific chemical properties to the rate constants for nonradiative exciton decay.
本文综述了吸附在半导体纳米晶体（量子点，QDs）表面的分子影响这些纳米结构中带内和带间激子弛豫途径及动力学的机制。在许多情况下，量子点的表面化学决定了热载流子带内冷却过程中俄歇弛豫与电子 - 振动能量转移之间的竞争，以及带边激子弛豫过程中电子或空穴俘获过程与辐射复合之间的竞争。后一种竞争决定了纳米晶体的光致发光量子产率，通过一组大多为唯象学的模型可以预测该产率，这些模型将具有特定化学性质的配体的表面覆盖率与非辐射激子衰减的速率常数联系起来。
