Wang Chenxu, Yan Lihe, Si Jinhai, Wang Ning, Li Ting, Hou Xun
Key Laboratory for Physical Electronics and Devices of the Ministry of Education and Shaanxi Key Laboratory of Photonics Technology for Information, School of Electronic Science and Engineering, Xi'an Jiaotong University, No.28, Xianning West Road, Xi'an, 710049, China.
Small Methods. 2024 Dec;8(12):e2400241. doi: 10.1002/smtd.202400241. Epub 2024 Apr 21.
All-inorganic lead halide perovskite nanocrystals (NCs) have been widely applied in optoelectronic devices owing to their excellent photoluminescence (PL) properties. However, poor stability upon exposure to water, UV light or heat strongly limits their practical application. Herein, CsPbBr@Pb-MOF composites with exceptional stability against water, UV light, and heat are synthesized by ultrasonic processing the precursors of lead-based MOF (Pb-MOF), oleylammonium bromide (OAmBr) and cesium oleate (Cs-OA) solutions at room temperature. Pb-MOF can not only provide the lead source for the in situ growth of CsPbBr NCs, but also the protective layer of perovskites NCs. The formed CsPbBr@Pb-MOF composites show a considerable PL quantum yield (PLQY) of 67.8%, and can maintain 90% of the initial PL intensity when immersed in water for 2 months. In addition, the outstanding PL stability against UV light and heat is demonstrated with CsPbBr NCs synthesized by the conventional method as a comparison. Finally, a green (light-emitting diode) LED is fabricated using green-emitting CsPbBr@Pb-MOF composites and exhibits excellent stability without packaging when immersed in water for 30 days. This study provides a practical approach to improve the stability in aqueous phase, which may pave the way for future applications for various optoelectronic devices.
全无机铅卤化物钙钛矿纳米晶体（NCs）因其优异的光致发光（PL）特性而被广泛应用于光电器件中。然而，暴露于水、紫外光或热时稳定性较差，这严重限制了它们的实际应用。在此，通过在室温下超声处理铅基金属有机框架（Pb-MOF）、油基溴化铵（OAmBr）和油酸铯（Cs-OA）溶液的前驱体，合成了对水、紫外光和热具有优异稳定性的CsPbBr@Pb-MOF复合材料。Pb-MOF不仅可以为CsPbBr NCs的原位生长提供铅源，还可以作为钙钛矿NCs的保护层。所形成的CsPbBr@Pb-MOF复合材料显示出相当可观的67.8%的PL量子产率（PLQY），并且当浸入水中2个月时可以保持初始PL强度的90%。此外，与通过传统方法合成的CsPbBr NCs相比，证明了其对紫外光和热具有出色的PL稳定性。最后，使用绿色发光的CsPbBr@Pb-MOF复合材料制造了绿色（发光二极管）LED，并且在浸入水中30天时无封装情况下表现出优异的稳定性。这项研究提供了一种提高水相中稳定性的实用方法，这可能为各种光电器件的未来应用铺平道路。
