Highly efficient stable blue organic light-emitting diodes based on a novel anthracene[2,3-b]benzofuran framework

Abstract

Organic blue fluorescent emitters’ emissions are highly desirable for high-resolution organic light-emitting diode (OLED) display technology. In this work, a design strategy to realize narrowband emission of organic blue fluorescent emitters by connecting carbazole and amine, named ABFCz and ABFAn, respectively, with anthracene[2,3-b]benzofuran as rigid groups is reported for the first time. The developed materials can achieve high efficiency and long life. Studies of the doped devices show that ABFCz-based blue-emitting OLEDs achieve a maximum current efficiency of 6.96 cd A−1 with a narrow full width at half maximum (FWHM) of 44 nm, as well as a Commission Internationale de l’Eclairage (CIE) coordinate of (0.15, 0.14). A maximum external quantum efficiency (EQEmax) of 7.7% is also achieved. Meanwhile, the ABFAn emitter-based devices exhibit blue emission with a maximum current efficiency of up to 9.20 cd A−1 (EQEmax of 11.4%) with a FWHM of 44 nm, as well as a CIE coordinate of (0.14, 0.13). The devices are based on an ABFAn operating lifetime test LT90 (luminance decays to 90% of the initial brightness) of 202 h at an initial luminance of 1000 cd m−2. The results show that anthracene[2,3-b]benzofuran can be modified with a higher glass transition temperature (T g) to achieve high-efficiency and stable-operating-lifetime blue light devices. Our work may provide a new approach for designing high-efficiency blue materials.