Tandem organic light-emitting devices (TOLEDs) satisfy the requirements of various applications owing to their high luminance, high efficiency, and long lifetime. A crucial factor in achieving optimal electroluminescence (EL) performance is the host material used for the emitting layer. In this study, a series of benzothiazole (BTZ)-based materials were linked via a phenyl bridge to three different electron-donor moieties, i.e., phenothiazine (PTZ), dimethylacridine (DMAC), and carbazole (CZ), named BTZ-PTZ, BTZ-DMAC, and BTZ-CZ, as bipolar hosts for green phosphors to realize ultra-high efficiency organic light-emitting devices (OLEDs). A Ir(ppy)₃-based device based on a BTZ-CZ host is shown to exhibit a satisfactory peak efficiency of 28.0 % (98.8 cd A⁻¹ and 111.6 lm W⁻¹). Additionally, highly efficient green TOLEDs based on a BTZ-CZ host are demonstrated, and they are constructed with a specific charge generation layer and a TiO₂ nanoparticle-based internal light extraction structure. The proposed TOLEDs achieved a maximum efficiency of 64.4 % (223.6 cd A⁻¹ and 138.1 lm W⁻¹) and a high maximum luminance of 24.9 × 10⁴ cd m⁻², one of the highest levels of efficiency and luminance reported in the literature for Ir(ppy)₃-based tandem devices. These results show that the ingenious BTZ-based bipolar hosts exhibit immense potential for the development of tandem OLEDs, thus facilitating the realization of various high-performance EL applications.

串联有机发光器件（TOLED）因其高亮度、高效率和长寿命而满足各种应用的要求。实现最佳电致发光 (EL) 性能的关键因素是用于发光层的主体材料。在这项研究中，一系列苯并噻唑（BTZ）基材料通过苯基桥连接到三个不同的电子给体部分，即吩噻嗪（PTZ）、二甲基吖啶（DMAC）和咔唑（CZ），命名为BTZ-PTZ、BTZ-DMAC和BTZ-CZ作为绿色荧光粉的双极主体，以实现超高效有机发光器件（OLED）。基于BTZ-CZ的Ir(ppy) _3器件主体显示出令人满意的 28.0% 峰值效率（98.8 cd A ^-1和 111.6 lm W ^-1）。此外，还展示了基于BTZ-CZ主体的高效绿色TOLED ，它们由特定的电荷生成层和基于TiO _{2纳米粒子的内部光提取结构构成。}所提出的 TOLED 实现了 64.4% 的最大效率（223.6 cd A ^-1和 138.1 lm W ^{-1 ）和 24.9 × 10 4}  cd m ^-2的高最大亮度，这是报告中效率和亮度最高水平之一。 Ir(ppy) ₃的文献基于串联装置。这些结果表明，巧妙的基于 BTZ 的双极主体在串联 OLED 的开发方面表现出巨大的潜力，从而有助于实现各种高性能 EL 应用。