Heavy-Atom-Free Room-Temperature Phosphorescent Organic Light-Emitting Diodes Enabled by Excited States Engineering

Room
temperature phosphorescence materials offer great opportunities
for applications in optoelectronics, due to their unique photophysical
characteristics. However, heavy-atom-free organic emitters that can
realize distinct electrophosphorescence are rarely exploited. Herein
a new approach for designing heavy-atom-free organic room temperature
phosphorescence emitters for organic light-emitting diodes is presented.
The subtle tuning of the singlet and triplet excited states energies
by appropriate choice of host matrix allows tailored emission properties
and switching of emission channels between thermally activated delayed
fluorescence and room temperature phosphorescence. Moreover, an efficient
and heavy-atom-free room temperature phosphorescence organic light-emitting
diode using the developed emitter is realized.

室温磷光（room temperature phosphorescence）材料凭借其独特的光物理特性，在光电子学领域拥有巨大的应用潜力。然而，能够实现清晰电致磷光的无重原子（heavy-atom-free）有机发光体却极少被开发。本文提出了一种面向有机发光二极管（organic light-emitting diodes）的无重原子有机室温磷光发光体的全新设计策略。通过合理选取主体基质对单重激发态与三重激发态的能级进行精细调控，可实现发射性能的定制化，并实现热激活延迟荧光（thermally activated delayed fluorescence）与室温磷光之间的发射通道切换。此外，基于所开发的发光体，我们成功制备出高效且无重原子的室温磷光型有机发光二极管。