Letter pubs.acs.org/NanoLett
Defect-Induced Conical Intersections Promote Nonradiative Recombination Yinan Shu, B. Scott Fales, and Benjamin G. Levine* Department of Chemistry, Michigan State University, East Lansing, Michigan 48824, United States
Downloaded by UNIV OF SUSSEX on August 24, 2015 | http://pubs.acs.org Publication Date (Web): August 24, 2015 | doi: 10.1021/acs.nanolett.5b02848
S Supporting Information *
ABSTRACT: We apply multireference electronic structure calculations to demonstrate the presence of conical intersections between the ground and the first excited electronic states of three silicon nanocrystals containing defects characteristic of the oxidized silicon surface. These intersections are accessible upon excitation at visible wavelengths and are predicted to facilitate nonradiative recombination with a rate that increases with decreasing particle size. This work illustrates a new framework for identifying defects responsible for nonradiative recombination.
KEYWORDS: Nonradiative recombination, silicon nanoparticles, silicon−silicon oxide interface, trap state, conical intersection, graphics processing units
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molecules do and that the presence of a CI meeting the above criteria may indicate that a particular defect facilitates nonradiative recombination. Though a recent groundbreaking study has attributed the cooling of hot electrons in semiconductor nanoparticles to cascades of CIs between excited states,33 to date, the hypothesis that defect-induced CIs between the ground and first excited state facilitate recombination has only been investigated in molecule-sized cluster models (
