Fine regulation of linker and donor moieties to construct benzimidazole-based blue emitters for high-efficient organic light-emitting diodes

摘要

The investigation and development of novel blue emitters are still necessary for the fabrication of high-efficient organic light-emitting diodes (OLEDs). Benzimidazole and its derivatives have been attracting extensive attention due to the special characterizations to achieve high device efficiency. However, the systematic elucidation of the relationship between structure and properties is rarely reported. In this paper, four benzimidazole derivatives with virus linker and donor units were designed and synthesized, named PI-AN-3-Cz, PI-NP-3-Cz, PI-AN-TPA, and PI-NP-TPA. Their absorption, photoluminescence, electrochemistry, and thermology were systematically studied, and the results were found to be potential candidates for emitters of OLEDs. Interestingly, the fabricated OLEDs with PI-AN-3-Cz as emitter showed the best performance with the efficiencies of 13.75 cd/A, 5.87 lm/W, and 8.55%. Furthermore, it can be observed that these linkers/donors are changed from anthracene to naphthalene/carbazole to triphenylamine, the corresponding emission moved from sky to violet blue with commission international De L' Eclairage (CIE) of (0.151, 0.055). The findings give a guidance for the preparation of adjustable emission and high-efficient benzimidazole derivatives.