Two new host materials, CzDPPy and tCzDPPy, were designed and synthesized through the Ullmann-coupling reaction between carbazole/3,6-di-tert-butyl-carbazole and 2,6-bis(2-bromophenyl)pyridine. Their single-crystal structure, thermal, electrochemical, opt-electronic and bipolar carrier-transporting properties were fully investigated. Due to the steric hindrance of carbazole at the ortho positions of diphenylpyridine, both CzDPPy and tCzDPPy adapted highly twisted molecular conformation, which could effectively minimize their π conjugation and endow them the high triplet energies of 2.67 and 2.64 eV, respectively. Organic light-emitting devices (OLEDs) were fabricated by using CzDPPy and tCzDPPy as the host materials and 1,2-bis(carbazol-9-yl)-4,5-dicyanobenzene (2CzPN) as the sky-blue TADF emitter. The peak current efficiency of 34.8 cd A⁻¹, power efficiency of 33.1 lm W⁻¹ and external quantum efficiency of 16.0% were realized for the CzDPPy-based TADF OLED, along with the satisfactory CIE coordinate of (0.18, 0.34) at 100 cd m⁻².

通过咔唑/ 3,6-二叔丁基咔唑与2,6-双（2-溴苯基）吡啶之间的乌尔曼偶合反应，设计并合成了两种新的主体材料CzDPPy和tCzDPPy 。对它们的单晶结构，热，电化学，光电和双极载流子传输性质进行了充分研究。由于咔唑在邻位的位阻在二苯基吡啶的位置，CzDPPy和tCzDPPy都适应了高度扭曲的分子构象，可以有效地最小化它们的π共轭，并赋予它们分别为2.67和2.64 eV的高三重态能量。通过使用CzDPPy和tCzDPPy作为主体材料并使用1,2-双（咔唑-9-基）-4,5-二氰基苯（2CzPN）作为天蓝色TADF发射器来制造有机发光器件（OLED）。基于CzDPPy的TADF OLED实现了34.8 cd A ^-1的峰值电流效率，33.1 lm W ^-1的功率效率和16.0％的外部量子效率，以及100时（0.18，0.34）的令人满意的CIE坐标cd m ^-2。