Gong Chenjie, Wang Shalong, Fan Wenxuan, Wang Jianfeng, Wang Wanjie, Cao Yanxia, Song Jizhong
School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, China.
Key Laboratory of Materials Physics of Ministry of Education, Laboratory of Zhongyuan Light, School of Physics, Zhengzhou University, Zhengzhou 450051, China.
ACS Appl Mater Interfaces. 2024 Nov 6;16(44):60556-60563. doi: 10.1021/acsami.4c13618. Epub 2024 Oct 23.
All-inorganic cesium lead halide perovskite CsPbX (X = Cl, Br, I, or mixed) nanocrystals (NCs) are emerging as promising candidates in light-emitting diodes (LEDs) owing to their excellent luminescent properties. However, CsPbX NCs are extremely susceptible to the elevated temperature associated with prolonged LED operation due to their low formation energy and soft ionic crystal structure. Here, CsPbBr NCs hybridized with ZrO were in situ synthesized by a rapid solvent-free method under an ambient environment for the first time, which was also suitable for large-scale production. The as-prepared CsPbBr/ZrO hybrid phosphor not only presented enhanced photoluminescence (PL) properties but also exhibited improved thermal stability. For example, the PL intensity of the CsPbBr/ZrO hybrid phosphor could retain 70% of the initial value at 130 °C, obviously higher than that of 34% for pure CsPbBr. The exceptional thermal stability of the CsPbBr/ZrO hybrid phosphor could be attributed to the introduction of ZrO, which effectively preserved the initial perovskite structure of CsPbBr during heat treatment, as confirmed by XRD results. The as-prepared CsPbBr/ZrO hybrid phosphor had great practical applications verified by the construction of white LEDs (WLEDs) with a luminance degradation of only 9% after continuous operation for 24 h at the initial luminance of 2000 cd m, which was significantly better than that of 63% for control WLEDs. The proposed thermally stable hybrid phosphor is expected to greatly contribute to the industrialization process of perovskites.
全无机铯铅卤化物钙钛矿CsPbX（X = Cl、Br、I或混合）纳米晶体（NCs）因其优异的发光性能而成为发光二极管（LED）中很有前景的候选材料。然而，CsPbX NCs由于其形成能低和离子晶体结构柔软，极易受到与LED长时间运行相关的高温影响。在此，首次在环境条件下通过快速无溶剂方法原位合成了与ZrO杂交的CsPbBr NCs，该方法也适用于大规模生产。所制备的CsPbBr/ZrO混合荧光粉不仅具有增强的光致发光（PL）性能，而且还表现出改善的热稳定性。例如，CsPbBr/ZrO混合荧光粉的PL强度在130°C时可保留初始值的70%，明显高于纯CsPbBr的34%。CsPbBr/ZrO混合荧光粉出色的热稳定性可归因于ZrO的引入，XRD结果证实，ZrO在热处理过程中有效地保留了CsPbBr的初始钙钛矿结构。所制备的CsPbBr/ZrO混合荧光粉具有很大的实际应用价值，通过构建白色发光二极管（WLED）得到验证，在初始亮度为2000 cd m下连续运行24 h后，亮度降解仅为9%，明显优于对照WLED的63%。所提出的热稳定混合荧光粉有望对钙钛矿的工业化进程做出巨大贡献。
