Pyrene-Modified Blue Emitters for OLED Applications: Efficiency and Stability Advancements

Abstract

Blue light materials have always posed a challenge in the OLED industry due to their high energy, which negatively impacts the stability of organic luminescent materials. Consequently, there is a significant disparity in efficiency and lifespan compared to red and green materials. In this study, we successfully synthesized three blue fluorescent luminescent materials with high fluorescence quantum efficiency by utilizing pyrene as the core. The 1,6-positions of pyrene were substituted with diphenylamine and further modified with methoxy, isopropyl, and dibenzofuran. These modifications were introduced to enhance efficiency, increase spatial site resistance, and improve structural rigidity. Each structure exhibits a maximum current efficiency of over 8.2 cd/A and a maximum external quantum efficiency (EQE) of more than 5.8%. Notably, the compound N1,N6-bis(4-isopropylphenyl)-N1,N6-bis(2-methoxyphenyl)pyrene-1,6-diamine (BD1), with methoxy modification, achieves a maximum current efficiency of 9.3 cd/A. Additionally, the compound N1,N6-bis(dibenzo[b,d]furan-4-yl)-N1,N6-di-o-tolylpyrene-1,6-diamine (BD2) exhibits significantly less EQE roll-off. This article provides valuable insights into the substitution-based modification strategy for optimizing blue light performance in OLED applications.