Tetraphenylethene-Triphenylamine Derivatives: Synthesis, Aggregation-Induced Emission Characteristic and Their Radioluminescent Applications

In traditional radioluminescent light sources (RLS), ZnS:Cu is mostly used as the phosphor, but the low conversion efficiency limits its further application. Until now, it is still extremely crucial and fundamental to improve the energy efficiency for this research area. Here, we proposed aggregation-induced emission (AIE) materials as the luminescent materials for RLS to improve the energy efficiency. Two new AIE materials based on tetraphenylvinyl-triphenylamine derivatives, TPE-TPAO and TPE-2TPAO, were designed and prepared through the Suzuki-Miyaura coupling. The radioluminescence efficiencies of the two materials were established by theoretical calculations. The properties of cathodoluminescent were measured by fluorescence spectrometer to simulate tritium-based radioluminescent light. The conjugation between TPE moieties and triphenylamine derivatives assures that TPE-TPAO and TPE-2TPAO both possess typical AIE characteristics. The absolute quantum yields of TPE-TPAO and TPE-2TPAO in solid state are as high as 95.5% and 74.9%, respectively. The calculated energy efficiency of radioluminescence for TPE-TPAO and TPE-2TPAO are 28% and 21%, respectively. The emission intensity of both materials increased with the increasing of accelerating voltage. At the same time, the cathodoluminescence intensity was related to the luminescence efficiency and particle size of materials. The research provided theoretical and experimental basis for the further acquisition of high-efficiency radioluminescence devices.