Despite the significant progress in organic light-emitting diodes (OLEDs), it is still challenging to produce blue OLEDs with sufficient color purity, stability, and efficiency for applications [[1], [2], [3]]. Hence, 9,9'-(4'-(4,6-diphenyl-1,3,5-triazin-2-yl)-[1,1′-biphenyl]-2,6-diyl) bis(3,6-di-tert-butyl-9H-carbazole) (DtCz-TRZ) and 9,9'-(4'-(4,6-diphenyl-1,3,5-triazin-2-yl)-[1,1′-biphenyl]-3,5-diyl) bis(3,6-di-tert-butyl-9H-carbazole) (mDtCz-TRZ) were designed and synthesized by introducing an additional benzene moiety to enlarge the distance of the donor and acceptor units. Thanks to the appropriate overlap of frontier molecular orbits (FMOs) and the extended molecular backbone that weakens the intramolecular charge transfer (ICT) process, structural relaxation and spectral redshift can be hindered, and efficient deep blue emission can be realized. Deep blue TADF-OLEDs achieved a maximum external quantum efficiency of 9.37% with an emission peak at 455 nm under a Commission Internationale de L'Eclairage (CIE) coordinates of (0.17, 0.18). To enhance the color purity, target compounds were employed as sensitizer and famous multiple resonances (MR)-TADF molecule v-DABNA as emitter, thermally activated sensitized fluorescence (TSF)-OLED based on mDtCz-TRZ shows EQE_max of 15.31% with electroluminescence (EL) spectrum peak at 473 nm, maximum luminance of close to 5000 cd m⁻², FWHM of 20 nm, respectively. The two blue TADF materials have demonstrated superior performance in TADF- and TSF-OLEDs, validating their versatile applications.

尽管有机发光二极管 (OLED) 取得了重大进展，但生产具有足够色纯度、稳定性和效率的蓝色 OLED 仍然具有挑战性 [ [1] , [2 ] , [ 3 ]]. 因此，9,9'-(4'-(4,6-二苯基-1,3,5-三嗪-2-基)-[1,1'-联苯基]-2,6-二基)双(3, 6-二叔丁基-9H-咔唑) (DtCz-TRZ) 和 9,9'-(4'-(4,6-二苯基-1,3,5-三嗪-2-基)-[1, 1'-联苯]-3,5-二基)双(3,6-二叔丁基-9H-咔唑)(mDtCz-TRZ)是通过引入额外的苯部分以扩大供体的距离而设计合成的和受体单位。由于前沿分子轨道（FMO）的适当重叠和减弱分子内电荷转移（ICT）过程的延伸分子主链，可以阻碍结构弛豫和光谱红移，并可以实现高效的深蓝色发射。深蓝色 TADF-OLED 在 Commission Internationale de L'Eclairage (CIE) 坐标 (0. 17, 0.18). 为了提高颜色纯度，目标化合物被用作敏化剂和著名的多重共振 (MR)-TADF 分子v -DABNA 作为发射体，基于 mDtCz-TRZ 的热激活敏化荧光 (TSF)-OLED 显示 EQE_最大值为 15.31%，电致发光 (EL) 光谱峰值在 473 nm，最大亮度接近 5000 cd m ^-2，FWHM 为分别为 20 纳米。这两种蓝色 TADF 材料在 TADF-OLED 和 TSF-OLED 中展示了卓越的性能，验证了它们的多功能应用。