Exciplex-triplet energy transfer: A new method to achieve extremely efficient organic light-emitting diode with external quantum efficiency over 30% and drive voltage below 3 V

Autor:	Nobuharu Ohsawa, Satoshi Seo, Shunpei Yamazaki, Satoko Shitagaki, Hiromi Nowatari, Hideko Inoue, Kunihiko Suzuki
Rok vydání:	2014
Předmět:	Materials science business.industry General Engineering General Physics and Astronomy OLED Optoelectronics Quantum efficiency Phosphorescence business Electrical efficiency Excitation Diode Common emitter Voltage
Zdroj:	Japanese Journal of Applied Physics. 53:042102
ISSN:	1347-4065 0021-4922
DOI:	10.7567/jjap.53.042102
Popis:	A novel approach to enhance the power efficiency of an organic light-emitting diode (OLED) by employing energy transfer from an exciplex to a phosphorescent emitter is reported. It was found that excitation energy of an exciplex formed between an electron-transporting material with a π-deficient quinoxaline moiety and a hole-transporting material with aromatic amine structure can be effectively transferred to a phosphorescent iridium complex in an emission layer of a phosphorescent OLED. Moreover, such an exciplex formation increases quantum efficiency and reduces drive voltage. A highly efficient, low-voltage, and long-life OLED based on this energy transfer is also demonstrated. This OLED device exhibited extremely high external quantum efficiency of 31% even without any attempt to enhance light outcoupling and also achieved a low drive voltage of 2.8 V and a long lifetime of approximately 1,000,000 h at a luminance of 1,000 cd/m2.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::7bd31ff918328744d855045924d5e64a https://doi.org/10.7567/jjap.53.042102 Zobrazit plný text záznamu