Efficient deep-blue thermally activated delayed fluorescence (TADF) emitters are still very scarce. It is available to render the color bluer by reducing the intensity of intramolecular charge transfer (ICT) between acceptor and donor. Here, attaching the acceptor of six-membered heterocyclic diphenylsulfone-derivative (2PTO) with donors (DMAc and DPAc), two compounds, 2-(9,9-dimethyl-acridin-10(9H)-yl)-10-phenyl-10H-phenothiazine 5,5-dioxide (DMAC2PTO) and 2-(9,9-diphenylacridin-10(9H)-yl)-10-phenyl-10H-phenothiazine 5,5-dioxide (DPAC2PTO) were designed and synthesized. Due to the largely twisted configuration and weak ICT, DMAC2PTO with small singlet-triplet energy gap (ΔE_ST) displayed TADF feature and deep-blue emission. Moreover, DPAC2PTO exhibited much lower photoluminescence quantum yield (PLQY) than DMAC2PTO. The doped device of DMAC2PTO achieved a maximum external quantum efficiency (EQE_max) of 15.2% with a deep-blue color coordinate (CIE_x,y) of (0.154, 0.108), and showed a narrow emission spectra with a 52 nm full width at half maximum (FWHM). In addition, the non-doped device of DMAC2PTO reached the EQE_max of 8.36% with CIE_x,y of (0.158, 0.157).

高效的深蓝色热激活延迟荧光（TADF）发射器仍然非常稀缺。通过降低受体和供体之间的分子内电荷转移（ICT）的强度，可以使颜色更蓝。在这里，将六元杂环二苯砜衍生物（2PTO）的受体与供体（DMAc和DPAc）连接在一起，生成了两种化合物2-（9,9-二甲基-啶-10（9 H）-基）-10-苯基设计了-10 H-吩噻嗪5,5-二氧化物（DMAC2PTO）和2-（9,9-二苯基ac啶-10 （9 H）-基）-10-苯基-10 H-吩噻嗪5,5-二氧化物（DPAC2PTO）并合成。由于配置的扭曲和ICT的不足，DMAC2PTO单重态-三重态的能隙（ΔE _ST）较小，显示了TADF特征和深蓝色发射。此外，DPAC2PTO的光致发光量子产率（PLQY）比DMAC2PTO低得多。DMAC2PTO的掺杂器件实现了15.2％的最大外部量子效率（EQE _max），深蓝色坐标（CIE _x，y）为（0.154，0.108），并显示了窄的发射光谱，全宽为52 nm最大一半（FWHM）。此外，DMAC2PTO的非掺杂器件的EQE _max达到8.36％，CIE _x，y为（0.158，0.157）。