Photo luminescence properties related to localized states in colloidal PbS quantum dots
Photo luminescence properties related to localized states in colloidal PbS quantum dots
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DOI：
10.1016/j.jlumin.2005.12.033
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发表时间：
2006-07-01
影响因子：
3.6
通讯作者：
Nakayama, M
中科院分区：
文献类型：
--
作者：
Kim, DG;Kuwabara, T;Nakayama, M
研究了胶体法制备的PbS量子点的光致发光特性。将量子点分散到聚乙烯醇薄膜中，研究其光学性质与温度的关系。在可见光区，可以清楚地观察到吸收峰和发光峰。量子点中吸收能随温度的变化与块体晶体中的不同，通过考虑量子点中量子限制的热膨胀效应，定量地分析了这种依赖关系。光致发光光谱由三个光谱带组成，分为两类。其中两个10K时斯托克斯位移为0.25 eV和0.47 eV的发光带属于缺陷相关的光致发光带，另一个斯托克斯位移较小为0.17 eV的发光带在光致发光的温度依赖关系中表现出浅陷态的特征。(C)2006爱思唯尔B.V.保留所有权利。
We have investigated photoluminescence (PL) properties of PbS quantum dots (QDs) prepared by a colloidal method. The QDs were dispersed into polyvinyl alcohol films in order to investigate the temperature dependence of optical properties. In the visible region, both absorption and PL peaks are clearly observed. The temperature dependence of the absorption energy in QDs is quite different from that in a bulk crystal; the dependence is quantitatively analyzed by considering a thermal-expansion effect on the quantum confinement in QDs. The PL spectra are composed of three PL bands which are classified into two types. Two PL bands among them with the Stokes shifts of 0.25 and 0.47 eV at 10 K are attributed to the defect-related PL bands, and another with the relatively small Stokes shift of 0.17 eV exhibits characteristics of shallow trapped states in the temperature dependence of PL. (c) 2006 Elsevier B.V. All rights reserved.