Hebei Key Laboratory of Optic-Electronic Information and Materials, College of Physics Science and Technology, Hebei University, Baoding, 071002, China.
Department of Chemistry, Brown University, Providence, RI, 02912, USA.
Adv Mater. 2023 May;35(19):e2211235. doi: 10.1002/adma.202211235. Epub 2023 Mar 27.
Lead-free double perovskites have emerged as a promising class of materials with potential to be integrated into a wide range of optical and optoelectronic applications. Herein, the first synthesis of 2D Cs AgIn Bi Cl (0 ≤ x ≤ 1) alloyed double perovskite nanoplatelets (NPLs) with well controlled morphology and composition is demonstrated. The obtained NPLs show unique optical properties with the highest photoluminescence quantum yield of 40.1%. Both temperature dependent spectroscopic studies and density functional theory calculation results reveal that the morphological dimension reduction and In-Bi alloying effect together boost the radiative pathway of the self-trapped excitons of the alloyed double perovskite NPLs. Moreover, the NPLs exhibit good stability under ambient conditions and against polar solvents, which is ideal for all solution-processing of the materials in low-cost device manufacturing. The first solution-processed light-emitting diodes is demonstrated using the Cs AgIn Bi Cl alloyed double perovskite NPLs as the sole emitting component, showing luminance maximum of 58 cd m and peak current efficiency of 0.013 cd A . This study sheds light on morphological control and composition-property relationships of double perovskite nanocrystals, paving the way toward ultimate utilizations of lead-free perovskite materials in diverse sets of real-life applications.
无铅双钙钛矿作为一类很有前途的材料，具有集成到广泛的光学和光电应用的潜力。在此，首次合成了具有良好控制形貌和组成的二维 CsAgInBiCl（0≤x≤1）合金双钙钛矿纳米板（NPL）。所获得的 NPL 具有独特的光学性质，最高荧光量子产率为 40.1%。温度相关光谱研究和密度泛函理论计算结果均表明，形态维度降低和 In-Bi 合金化效应共同促进了合金双钙钛矿 NPL 自陷激子的辐射途径。此外，NPL 在环境条件和极性溶剂下表现出良好的稳定性，这对于低成本器件制造中材料的全溶液处理非常理想。首次使用 CsAgInBiCl 合金双钙钛矿 NPL 作为唯一发光组件演示了溶液处理发光二极管，显示出 58 cd m 的最大亮度和 0.013 cd A 的峰值电流效率。这项研究揭示了双钙钛矿纳米晶体的形态控制和组成-性能关系，为无铅钙钛矿材料在各种实际应用中的最终应用铺平了道路。
