华东理工大学朱为宏研究组报道了用于构建超高温X射线闪烁体的双约束非辐射有机离子主客体荧光粉。2025年3月20日出版的《美国化学会杂志》发表了这项成果。

在此，小组开发了基于有机离子主客体磷光系统的超高温闪烁体，具有前所未有的热稳定发射，最高可达673K。客体荧光粉具有自旋-振动耦合辅助的系统间交叉，有效地将磷光转化为热激活的延迟荧光，以克服三重态激子的热失活。同时，刚性离子主体和客体具有强静电相互作用，使激子的内在和外在非辐射最小化，即所谓的双约束非辐射。这两种机制协同作用，促成了室温磷光效率高达38.7%的高效三重态激子基发光和耐超高温双发射。这种创新的离子主客体闪烁体实现了71.5 nGy s^-1的极低X射线探测极限和非常明亮的光致发光（在483K时效率为80.4%），实现了超高温X射线成像。

据了解，具有X射线激发发光的闪烁体在医学放射照相、无损检测和高能物理等领域引起了广泛的关注。然而，热猝灭显著降低了辐射发光效率，特别是对于那些具有辐射诱导三重态激子利用前景的磷光闪烁体，最终限制了它们在高温场景中的应用。

附：英文原文

Title: Organic Ionic Host–Guest Phosphor with Dual-Confined Nonradiation for Constructing Ultrahigh-Temperature X-ray Scintillator

Author: Ying Wang, Jiahong Yu, Zixing Zhou, Weijun Zhao, Yilong Wang, Jiaqiang Zhao, Chenggong Ma, Zhen-Yi Lin, Yongzhen Wu, Xiao Wang, Huili Ma, Wei-Hong Zhu

Issue&Volume: March 20, 2025

Abstract: Scintillators with X-ray-excitable luminescence have attracted great attention in the fields of medical radiography, nondestructive inspection, and high-energy physics. However, thermal quenching significantly reduces radioluminescence efficiency, particularly for those phosphorescent scintillators with promising radiation-induced triplet exciton utilization, ultimately limiting their applications in high-temperature scenarios. Herein, we develop ultrahigh-temperature scintillators based on organic ionic host–guest phosphorescence systems with unprecedented thermal-stable emissions up to 673 K. The guest phosphor features spin-vibronic coupling-assisted intersystem crossing, effectively transforming phosphorescence to thermally activated delayed fluorescence for overcoming thermal inactivation of triplet excitons. Meanwhile, the rigid ionic host and guest with robust electrostatic interactions minimize both the intrinsic and extrinsic nonradiations of excitons, the so-called dual-confined nonradiation. These two mechanisms work synergistically, contributing to the highly efficient triplet exciton-based luminescence with a room-temperature phosphorescence efficiency of 38.7% and ultrahigh-temperature-resistant dual emissions. Such an innovative ionic host–guest scintillator achieves an impressively low X-ray detection limit of 71.5 nGy s–1 and remarkably bright photoluminescence (efficiency of 80.4% at 483 K), enabling ultrahigh-temperature X-ray imaging.

DOI: 10.1021/jacs.4c16935

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c16935