Stable deep blue photoluminescence from CsPbBr 3 quantum dots

作者：Shi-Jie Gao, Xiaohui Hu, Honglei Sun, Jiaqing Xu, Yufan Gu, Yunsong Di, Wei-Ping Zhou, Gangyi Zhu, Chunxiong Bao, Chong Sheng, Fengrui Hu, Zhixing Gan · 发表于：Nano Research · 年份：2025 · DOI：10.26599/nr.2025.94907792 · 被引用次数：3 · 研究领域：Perovskite Materials and Applications、Luminescence Properties of Advanced Materials、Optical properties and cooling technologies in crystalline materials

Despite recent progress, it remains challenging to fabricate stable deep blue-emitting perovskites. Here, we propose a molecular etching strategy to obtain ultra-small CsPbBr 3 perovskite quantum dots (QDs) with robust deep-blue emission. The diphenylalanine (FF) with high polarity is used to break ionic bonds of CsPbBr 3 to strip off atomic layers from the QDs. Simultaneously, perfluoroglutaric acid (PFGA) ligands are employed to passivate the QDs surface, effectively overcoming the surface defects induced by ligand detachment. By adjusting the volume ratio of QD:FF solutions, the emission wavelength can be continuously tuned from 506 nm to 458 nm, yielding deep-blue emission with high color purity. Comprehensive analyses using transient absorption, time-resolved photoluminescence (PL), and temperature-dependent PL measurements indicate that the emission blueshift is primarily attributed to the enhanced quantum confinement effects resulting from the reduced size. Furthermore, a dual-level optical encryption strategy is proposed by leveraging the intrinsically higher photostability of ultra-small CsPbBr 3 than that of mixed halide CsPb(Cl/Br) 3 QDs. This work provides a viable pathway for fabricating high-efficiency, ultra-stable deep-blue emitting perovskite QDs, showing significant potential for advanced applications in high-resolution displays and optoelectronic encryption.