Sung Young Mo, Kwon Eun Suk, Maruyama Yusuke Makida, Shin Youngsik, Ihn Soo-Ghang, Kim Jong Soo, Choi Hyeonho, Lee Hyo Sug, Kim Jung-Hwa, Kim Joonghyuk, Sul Soohwan
Analytical Engineering Group, Samsung Advanced Institute of Technology, 130, Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16678, South Korea.
Organic Materials Lab, Samsung Advanced Institute of Technology, 130, Samsung-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do, 16678, South Korea.
Phys Chem Chem Phys. 2022 Sep 21;24(36):21995-21999. doi: 10.1039/d2cp01394k.
Intramolecular charge transfer (ICT) plays a critical role in determining the photophysical properties of organic molecules, including their luminescence efficiencies. Twisted intramolecular charge transfer (TICT) is a process in which structural change accompanies ICT. Herein, we used time-resolved spectroscopy to study TICT in pyrene derivatives that are promising blue organic light emitting diode (OLED) emitter candidates; these derivatives show strong solvent-dependent charge-transfer (CT) behavior with unique fluorescence properties, increased fluorescence intensity in polar solvent. Slight structural changes that do not affect excited state dynamics were observed in nonpolar solvents, while polar solvents were found to affect excited state dynamics and CT characteristics, which affect their unusual fluorescence behavior. The TICT behavior of these pyrene derivatives can be modulated through structural modification. Our study provides valuable guidelines for the control of optical properties, including the luminescence efficiencies of OLED emitters that show TICT characteristics.
分子内电荷转移（ICT）在决定有机分子的光物理性质（包括其发光效率）方面起着关键作用。扭曲分子内电荷转移（TICT）是一种结构变化伴随ICT发生的过程。在此，我们使用时间分辨光谱来研究芘衍生物中的TICT，这些芘衍生物是有前景的蓝色有机发光二极管（OLED）发光体候选物；这些衍生物表现出强烈的溶剂依赖性电荷转移（CT）行为以及独特的荧光性质，即在极性溶剂中荧光强度增加。在非极性溶剂中观察到不影响激发态动力学的轻微结构变化，而发现极性溶剂会影响激发态动力学和CT特性，进而影响其异常的荧光行为。这些芘衍生物的TICT行为可以通过结构修饰来调节。我们的研究为控制光学性质提供了有价值的指导方针，包括对表现出TICT特性的OLED发光体的发光效率的控制。
