The importance of surface states in N-doped carbon quantum dots
The importance of surface states in N-doped carbon quantum dots
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DOI：
10.1016/j.carbon.2021.06.088
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发表时间：
2021-07-09
期刊：
影响因子：
10.9
通讯作者：
Svrcek, Vladimir
中科院分区：
文献类型：
--
作者：
Dsouza, Slavia Deeksha;Buerkle, Marius;Svrcek, Vladimir
采用常压微等离子体一步法制备了掺氮碳量子点。通过一系列的光学和化学测量以及理论计算的验证，研究了观测到的光致发光发射的来源及其与氮掺杂的关系。氮掺杂和表面态与氮和氧基团的官能化形成了一种杂化结构，这种杂化结构导致了量子产率高达33%的发光。载流子倍增被观察到是量子产率的阶梯式增强。对可见光发射的分析表明，大部分发射来自表面态，而不是由于量子点核心内的复合。在决定光学性质方面，表面官能团的作用比量子限制起主导作用。(C)2021年提交人。爱思唯尔有限公司出版。
Nitrogen-doped carbon quantum dots are synthesized by a one-step atmospheric pressure microplasma process. The origin of the observed photoluminescence emission and its relationship with nitrogen doping is studied using a range of optical and chemical measurements along with verification by theoretical calculations. Nitrogen doping into the core and functionalization of surface states with nitrogen and oxygen groups gives rise to a hybrid structure which is responsible for the luminescence with quantum yields up to 33%. Carrier multiplication is observed as a step-like enhancement in the quantum yield. The analysis of visible-light emission suggests that the emission originates for the most part from surface states and not due to recombination within the quantum dot core. The role of surface functional groups is dominant over quantum confinement in determining the optical properties. (C) 2021 The Authors. Published by Elsevier Ltd.