为获得新颖高效的热激活延迟荧光（TADF）材料，以二苯并吡啶并喹喔啉（BPQ）为受体（A），三苯胺（TPA）、吩噁嗪（PXZ）为供体（D），合成两种TADF材料：BPQPXZ和BPQTPA。研究表明，两种材料都具有典型的延迟荧光特性、较小的单重态与三重态的能级差（ΔE_ST）和较大的振子强度（f）。基于强受体强供体组合的BPQPXZ的器件实现了深红光发射，发射波长达到660 nm，但受能隙的影响，外量子效率（EQE）仅有1.0%。基于强受体弱供体组合的BPQTPA，因其TPA刚性小于PXZ，BPQTPA的供受体扭曲程度小，轨道交盖程度大，f更大，故BPQTPA具有更大的荧光量子产率（82.7%）。同时因TPA的给电子能力比PXZ弱，BPQTPA内电荷转移效应减小，导致发射峰蓝移，因此基于BPQTPA的器件发射555 nm的黄光，与BPQPXZ相比，BPQTPA器件的启亮电压降低至2.8 V，电流效率、功率效率分别提高了32倍和36倍，EQE提升了6倍，达到7.0 %。

Latent fingerprints (LFPs) at the crime scene are served as important clues to locate the trajectory of criminal behavior and portray the characteristics of the suspect. Therefore, visualizing LFPs is of considerable significance. In this work, the europium metal-organic framework (Eu-MOF) sensor was successfully constructed for sensitive detection of gallic acid (3,4,5-trihydroxybenzoic acid, GA) and visualization of the sweat LFPs. The boric-acid-modified Eu-MOF was prepared by using the simple one-pot solvothermal method using Eu as the metal ion center and 3,5-dicarboxybenzeneboronic acid (BBDC) as the organic ligand. The sensor showed desirable photoluminescent performance through the chelating of BBDC with Eu3+. The sensor exhibited the satisfactory linear relationship to GA in the range of 1 nM to 20 nM with a low detection limit of 0.34 nM under the optimized conditions. The prepared sensor with ideal selectivity to GA was successfully applied for visualizing LFPs on porous substrates with the high contrast and superior stability. Given the good performance of the sensor, all fingerprint images obtained from 1 200 samples presented clear friction ridges and met the identification criteria. Notably, the sensor had less impact on the subsequent deoxyribonucleic acid (DNA) detection, displaying a promising perspective for applications in extracting physical evidence of site investigation.