Emission from Trions in Carbon Quantum Dots
Emission from Trions in Carbon Quantum Dots
复制标题
碳量子点中 Trion 的发射
DOI：
10.1021/jp5114569
复制
发表时间：
2015-02-12
影响因子：
3.7
通讯作者：
Chu, Paul K.
中科院分区：
文献类型：
--
作者：
Hao, Yanling;Gan, Zhixing;Chu, Paul K.
由活性炭在HNO 3溶液中制备的1 ~ 6 nm大尺寸碳量子点（CQD）的光致发光（PL）光谱显示出与激发波长无关的蓝光发射以及依赖于激发波长的长波长发射。研究了这两种发射对pH的依赖关系，实验结果表明，长波发射的峰位不随pH变化;但随着pH的升高，蓝色发射变得更加不对称，并出现明显的肩峰。提出了一个基于CQD中的缺陷束缚的trions的模型来解释在高pH下蓝色发射的肩峰，并且计算结果与关于trions与激子发射的积分强度比随pH的变化的实验数据吻合得很好。我们的实验和理论结果首次证明了CQD中trions的发射。
The photoluminescence (PL) spectra acquired from 1 to 6 nm large carbon quantum dots (CQDs) prepared by refluxing activated carbon in HNO3 show blue emission independent of the excitation wavelength as well as long-wavelength emission depending on the excitation wavelength. The dependence of the two emissions on pH is investigated, and the experimental results show that the peak position of the long-wavelength emission does not change with pH; however, the blue emission becomes more asymmetrical, and obvious shoulder peaks emerge as the pH increases. A model based on defect-bound trions in the CQDs is proposed to explain the shoulder peaks in the blue emission at high pH, and the calculated results agree well with experimental data concerning the integral intensity ratio of the trion to exciton emissions versus pH. Our experimental and theoretical results demonstrate for the first time emission from trions in CQDs.