Yang Yunfeng, Wang Yixuan, Bai Fu-Quan, Li Shun-Xin, Yang Qing, Wang Weibin, Yang Xinyi, Zou Bo
State Key Laboratory of Superhard Materials, Synergetic Extreme Condition High-Pressure Science Center, College of Physics, Jilin University, Changchun 130012, China.
Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
Nano Lett. 2024 Aug 14;24(32):9898-9905. doi: 10.1021/acs.nanolett.4c02174. Epub 2024 Jul 15.
The technology of combining multiple emission centers to exploit white-light-emitting (WLE) materials by taking advantage of porous metal-organic frameworks (MOFs) is mature, but preparing undoped WLE MOFs remains a challenge. Herein, a pressure-treated strategy is reported to achieve efficient white photoluminescence (PL) in undoped [Zn(Tdc)(py)] nanocrystals (NCs) at ambient conditions, where the Commission International del'Eclairage coordinates and color temperature reach (0.31, 0.37) and 6560 K, respectively. The initial [Zn(Tdc)(py)] NCs exhibit weak-blue PL consisting of localized excited (LE) and planarized intramolecular charge transfer (PLICT) states. After pressure treatment, the emission contributions of LE and PLICT states are balanced by increasing the planarization of subunits, thereby producing white PL. Meanwhile, the reduction of nonradiative decay triggered by the planarized structure results in 5-fold PL enhancement. Phosphor-converted light-emitting diodes based on pressure-treated samples show favorable white-light characteristics. The finding provides a new platform for the development of undoped WLE MOFs.
利用多孔金属有机框架（MOF）结合多个发射中心来开发白色发光（WLE）材料的技术已经成熟，但制备未掺杂的WLE MOF仍然是一个挑战。在此，报道了一种压力处理策略，以在环境条件下在未掺杂的[Zn（Tdc）（py）]纳米晶体（NCs）中实现高效的白色光致发光（PL），其中国际照明委员会坐标和色温分别达到（0.31，0.37）和6560 K。初始的[Zn（Tdc）（py）] NCs表现出由局域激发（LE）和平坦化分子内电荷转移（PLICT）态组成的弱蓝色PL。经过压力处理后，通过增加亚基的平面化来平衡LE和PLICT态的发射贡献，从而产生白色PL。同时，由平面化结构引发的非辐射衰减的减少导致PL增强了5倍。基于压力处理样品的磷光转换发光二极管显示出良好的白光特性。这一发现为未掺杂WLE MOF的开发提供了一个新平台。
