Yan Dongdong, Mo Qionghua, Zhao Shuangyi, Cai Wensi, Zang Zhigang
Key Laboratory of Optoelectronic Technology & Systems (Ministry of Education), Chongqing University, Chongqing 400044, China.
Nanoscale. 2021 Jun 3;13(21):9740-9746. doi: 10.1039/d1nr01492g.
With a high photoluminescence quantum yield (PLQY) being able to exceed 90% for those prepared by the hot injection method, CsPbBr3 quantum dots (QDs) have attracted intensive attention for white light-emitting diodes (WLEDs). However, the whole process is carried out in a 3-neck flask via air isolation and at a relatively high temperature. In addition, CsPbBr3 QDs suffer from poor stability under ambient atmosphere. In this work, an effective strategy through doping of Sn2+ ions at room-temperature is proposed to improve the emission efficiency and stability of CsPbBr3 QDs. Compared with pure CsPbBr3 QDs, a higher PLQY and a better stability are obtained. The detailed physical mechanism for this performance enhancement is discussed and described. An optimum result is found at an Sn2+ doping amount of 20%, which shows a high PLQY of 82.77%. WLEDs based on these 20% Sn2+ doped CsPbBr3 QDs are also studied, exhibiting a high color rendering index of 89 and a correlated color temperature (CCT) of 3954. The method proposed here provides an effective strategy to enhance the fluorescence and stability of CsPbBr3 QDs, which might have promising potential in the lighting fields.
通过热注入法制备的CsPbBr3量子点（QDs）具有高光致发光量子产率（PLQY），能够超过90%，因此在白光发光二极管（WLEDs）领域引起了广泛关注。然而，整个过程是在三口烧瓶中通过空气隔离并在相对较高的温度下进行的。此外，CsPbBr3量子点在环境大气中稳定性较差。在这项工作中，提出了一种在室温下通过掺杂Sn2+离子来提高CsPbBr3量子点发光效率和稳定性的有效策略。与纯CsPbBr3量子点相比，获得了更高的PLQY和更好的稳定性。讨论并描述了这种性能增强的详细物理机制。在Sn2+掺杂量为20%时发现了最佳结果，其显示出82.77%的高光致发光量子产率。还研究了基于这些20% Sn2+掺杂CsPbBr3量子点的白光发光二极管，其显色指数高达89，相关色温（CCT）为3954。这里提出的方法提供了一种增强CsPbBr3量子点荧光和稳定性的有效策略，在照明领域可能具有广阔的应用前景。
