Kim Jiyun, Jeong Suhyeon, Park Sangwook, Oh Saeyoung, Lee Kiho, Lee Soonhang, Lee Jihoon, Lee Hayoon, Park Jongwook
Integrated Engineering, Department of Chemical Engineering, Kyung Hee University, Yongin 17104, Republic of Korea.
Department of Polymer Science and Engineering and Department of IT∙Energy Convergence (BK21 FOUR), Korea National University of Transportation, Chungju 27469, Republic of Korea.
Materials (Basel). 2025 Apr 30;18(9):2058. doi: 10.3390/ma18092058.
Two innovative dimeric derivatives of indolo[3,2,1-jk]carbazole (ICz), named 7,7'-biindolo[3,2,1-jk]carbazole (ICzDO) and 4,4'-biindolo[3,2,1-jk]carbazole (ICzDM), have been developed. Both dimers consist of two ICz units coupled through distinct ortho and meta positions. In the solution state, ICzDO and ICzDM exhibited photoluminescence (PL) maxima at 379 nm and 391 nm, demonstrating emission in the deep-blue region. These compounds show exceptionally narrow emission spectra, characterized by full width at half maximum (FWHM) of 28 nm for ICzDO and 26 nm for ICzDM. In the film state, ICzDM exhibited a photoluminescence (PL) maximum at 428 nm, whereas ICzDO showed a red-shifted emission at 507 nm with a broad full width at half maximum (FWHM) of 87 nm, indicating significant red-shifted excimer emission characteristics. This is attributed to its aggregation-enhanced excimer emission (AEEE) characteristics. When used as host materials for red phosphorescent OLEDs, both compounds enabled efficient energy transfer. Devices using ICzDM as the host attained highly efficient external quantum efficiency (EQE) values of 13.5%, coupled with remarkable color purity represented by Commission Internationale de l'Éclairage (CIE) coordinates of (0.685, 0.314). These findings emphasize how strategic variations in linking positions of identical chromophores can markedly enhance OLED device performance, paving the way for innovative material designs in next-generation organic semiconductor technologies.
已开发出两种吲哚并[3,2,1-jk]咔唑（ICz）的创新二聚体衍生物，分别命名为7,7'-联吲哚并[3,2,1-jk]咔唑（ICzDO）和4,4'-联吲哚并[3,2,1-jk]咔唑（ICzDM）。这两种二聚体均由两个通过不同的邻位和间位连接的ICz单元组成。在溶液状态下，ICzDO和ICzDM的光致发光（PL）最大值分别在379 nm和391 nm处，表明在深蓝色区域发射。这些化合物显示出异常窄的发射光谱，ICzDO的半高宽（FWHM）为28 nm，ICzDM的半高宽为26 nm。在薄膜状态下，ICzDM的光致发光（PL）最大值在428 nm处，而ICzDO在507 nm处显示出红移发射，半高宽（FWHM）为87 nm，表明具有显著的红移准分子发射特性。这归因于其聚集增强准分子发射（AEEE）特性。当用作红色磷光OLED的主体材料时，这两种化合物都能实现有效的能量转移。使用ICzDM作为主体的器件获得了13.5%的高效外量子效率（EQE）值，以及由国际照明委员会（CIE）坐标（0.685, 0.314）表示的出色色纯度。这些发现强调了相同发色团连接位置的策略性变化如何显著提高OLED器件性能，为下一代有机半导体技术中的创新材料设计铺平了道路。
