缺陷诱导的单个外延InGaAs量子点的光致发光闪烁

Defect-induced photoluminescence blinking of single epitaxial InGaAs quantum dots.

作者信息

Hu Fengrui, Cao Zengle, Zhang Chunfeng, Wang Xiaoyong, Xiao Min

机构信息

National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China.

1] National Laboratory of Solid State Microstructures and School of Physics, Nanjing University, Nanjing 210093, China [2] Department of Physics, University of Arkansas, Fayetteville, AR 72701, USA.

出版信息

Sci Rep. 2015 Mar 10;5:8898. doi: 10.1038/srep08898.

DOI:10.1038/srep08898

PMID:25754220

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC4354043/

Abstract

Here we report two types of defect-induced photoluminescence (PL) blinking behaviors observed in single epitaxial InGaAs quantum dots (QDs). In the first type of PL blinking, the "off" period is caused by the trapping of hot electrons from the higher-lying excited state (absorption state) to the defect site so that its PL rise lifetime is shorter than that of the "on" period. For the "off" period in the second type of PL blinking, the electrons relax from the first excited state (emission state) into the defect site, leading to a shortened PL decay lifetime compared to that of the "on" period. This defect-induced exciton quenching in epitaxial QDs, previously demonstrated also in colloidal nanocrystals, confirms that these two important semiconductor nanostructures could share the same PL blinking mechanism.

摘要

在此，我们报告了在单个外延 InGaAs 量子点（QD）中观察到的两种缺陷诱导的光致发光（PL）闪烁行为。在第一种 PL 闪烁类型中，“关”周期是由热电子从较高激发态（吸收态）捕获到缺陷位点引起的，因此其 PL 上升寿命比“开”周期短。对于第二种 PL 闪烁类型中的“关”周期，电子从第一激发态（发射态）弛豫到缺陷位点，导致与“开”周期相比 PL 衰减寿命缩短。外延量子点中这种缺陷诱导的激子猝灭，此前在胶体纳米晶体中也有证明，证实了这两种重要的半导体纳米结构可能共享相同的 PL 闪烁机制。