The precise regulation of excited state is a challenge to emitters for achieving highly efficient non-doped deep-red electroluminescence (EL). Herein, we used triphenylamine and phenoxazine as donors and benzo[c][1,2,5]thiadiazole as an acceptor to construct a hot exciton skeleton. Then chemically modified the phenoxazine by locally large twisted conformation to obtain N,N-diphenyl-4-(7-(10-phenyl-10H-phenoxazin-3-yl)benzo[c][1,2,5]thiadiazol-4-yl)aniline (TPAPH), 4-(7-(10-(4-ethoxyphenyl)-10H-phenoxazin-3-yl)benzo[c][1,2,5]thiadiazol-4-yl)-N,N-diphenylaniline (TPAPHOC2), and 4-(3-(7-(4-(diphenylamino)phenyl)benzo[c][1,2,5]thiadiazol-4-yl)-10H-phenoxazin-10-yl)benzonitrile (TPAPHCN), thereby achieving excited state perturbation. As a result, three emitters exhibited aggregation-induced emission enhancement and hybridized local and charge transfers characteristics based on photophysical experimentals. In EL, the TPAPH-, TPAPHOC2-, and TPAPHCN-based non-doped devices achieved deep-red emission with Commission International de L’Eclairage coordinates of (0.68, 0.32), (0.69, 0.31), and (0.66, 0.34) and with emission peaks at 660, 669, and 647 nm, respectively. The maximum external quantum efficiencies were 5.3%, 3.7%, and 6.0%, respectively. The results of this study not only realize the non-doped deep-red OLEDs with high performance but also indicate that the presence of locally large twisted conformation presented an efficient manner for exploring precise excited state tuning for fluorescent emitter.

激发态的精确调节是发射器实现高效非掺杂深红色电致发光 (EL) 的挑战。在此，我们使用三苯胺和吩恶嗪作为供体，苯并[c][1,2,5]噻二唑作为受体来构建热激子骨架。然后通过局部大扭曲构象对吩恶嗪进行化学修饰，得到N , N -diphenyl-4-(7-(10-phenyl-10H-phenoxazin-3-yl)benzo[c][1,2,5]thiadiazol-4 -yl)苯胺 (TPAPH), 4-(7-(10-(4-ethoxyphenyl)-10 H -phenoxazin-3-yl)benzo[c][1,2,5]thiadiazol-4-yl) -N , N-二苯基苯胺 (TPAPHOC2), 和 4-(3-(7-(4-(二苯基氨基)苯基)苯并[c][1,2,5]thiadiazol-4-yl)-10 H-phenoxazin-10-yl)benzonitrile (TPAPHCN)，从而实现激发态扰动。结果，基于光物理实验，三个发射器表现出聚集诱导的发射增强和混合的局部和电荷转移特性。在 EL 中，基于 TPAPH、TPAPHOC2 和 TPAPHCN 的非掺杂器件实现了深红色发射，国际委员会 de L'Eclairage 坐标为 (0.68, 0.32)、(0.69, 0.31) 和 (0.66, 0.34)发射峰分别在 660、669 和 647 nm。最大外量子效率分别为 5.3%、3.7% 和 6.0%。