Effect of Chloride Passivation on Recombination Dynamics in CdTe Colloidal Quantum Dots.
Effect of Chloride Passivation on Recombination Dynamics in CdTe Colloidal Quantum Dots.
复制标题
DOI：
10.1002/cphc.201402753
复制
发表时间：
2015-04-27
期刊：
影响因子：
--
通讯作者：
Binks DJ
中科院分区：
文献类型：
--
作者：
Espinobarro-Velazquez D;Leontiadou MA;Page RC;Califano M;O'Brien P;Binks DJ
胶体量子点（CQD）可以与有机电荷传输层结合使用，以生产发光二极管，太阳能电池和其他设备。CQD在这些应用中的功效由于与表面陷阱相关的非辐射复合而降低。在这里，我们调查的影响，这些表面陷阱的钝化的CdTe量子点的复合动力学的氯离子。在这些钝化的CQD中，辐射复合占主导地位，其中辐射寿命在τr=20-55 ns内与CQD体积成线性比例。在氯化物钝化之前或暴露于空气之后，在复合瞬态中也观察到两个非辐射成分，样品依赖的寿命通常小于1 ns和几ns。的非辐射动力学可以解释由俄歇介导的捕获的空穴和寿命的原子模型计算的这个过程是一致的实验值，如果假设表面氧化的CQD。
Colloidal quantum dots (CQDs) can be used in conjunction with organic charge-transporting layers to produce light-emitting diodes, solar cells and other devices. The efficacy of CQDs in these applications is reduced by the non-radiative recombination associated with surface traps. Here we investigate the effect on the recombination dynamics in CdTe CQDs of the passivation of these surface traps by chloride ions. Radiative recombination dominates in these passivated CQDs, with the radiative lifetime scaling linearly with CQD volume over τr=20–55 ns. Before chloride passivation or after exposure to air, two non-radiative components are also observed in the recombination transients, with sample-dependent lifetimes typically of less than 1 ns and a few ns. The non-radiative dynamics can be explained by Auger-mediated trapping of holes and the lifetimes of this process calculated by an atomistic model are in agreement with experimental values if assuming surface oxidation of the CQDs.