High-efficiency blue phosphorescence emission is essential for organic optoelectronic applications. However, synthesizing heavy-atom-free organic systems having high triplet energy levels and suppressed non-radiative transitions—key requirements for efficient blue phosphorescence—has proved difficult. Here we demonstrate a simple chemical strategy for achieving high-performance blue phosphors, based on confining isolated chromophores in ionic crystals. Formation of high-density ionic bonds between the cations of ionic crystals and the carboxylic acid groups of the chromophores leads to a segregated molecular arrangement with negligible inter-chromophore interactions. We show that tunable phosphorescence from blue to deep blue with a maximum phosphorescence efficiency of 96.5% can be achieved by varying the charged chromophores and their counterions. Moreover, these phosphorescent materials enable rapid, high-throughput data encryption, fingerprint identification and afterglow display. This work will facilitate the design of high-efficiency blue organic phosphors and extend the domain of organic phosphorescence to new applications.

高效蓝色磷光发射对于有机光电应用至关重要。然而，事实证明，合成具有高三线态能级和抑制非辐射跃迁（有效蓝色磷光的关键要求）的无重原子有机系统很困难。在这里，我们展示了一种实现高性能蓝色荧光粉的简单化学策略，该策略基于将孤立的发色团限制在离子晶体中。在离子晶体的阳离子和发色团的羧酸基团之间形成高密度离子键导致分离的分子排列，发色团间的相互作用可以忽略不计。我们展示了从蓝色到深蓝色的可调磷光，最大磷光效率为 96。5% 可以通过改变带电发色团及其抗衡离子来实现。此外，这些磷光材料可实现快速、高吞吐量的数据加密、指纹识别和余辉显示。这项工作将促进高效蓝色有机荧光粉的设计，并将有机磷光领域扩展到新的应用领域。