Nearly 100% internal quantum efficiency in undoped electroluminescent devices employing pure organic emitters

Qisheng Zhang; Daniel Tsang; Hirokazu Kuwabara; Yasuhiro Hatae; Bo Li; Takehiro Takahashi; Sae Youn Lee; Takuma Yasuda; Chihaya Adachi

doi:10.1002/adma.201405474

Nearly 100% internal quantum efficiency in undoped electroluminescent devices employing pure organic emitters

Adv Mater. 2015 Mar 25;27(12):2096-100. doi: 10.1002/adma.201405474. Epub 2015 Feb 13.

Authors

Qisheng Zhang¹, Daniel Tsang, Hirokazu Kuwabara, Yasuhiro Hatae, Bo Li, Takehiro Takahashi, Sae Youn Lee, Takuma Yasuda, Chihaya Adachi

Affiliation

¹ Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan; JST, ERATO, Adachi Molecular Exciton Engineering Project c/o Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan.

PMID: 25678335
DOI: 10.1002/adma.201405474

Abstract

The design of efficient and concentration-insensitive metal-free thermally activateddelayed fluorescence (TADF) materials is reported. Blue and green organic light-emitting diodes (OLEDs) containing a hole-transport layer, an undoped TADF emissive layer, and an electron-transport layer achieve maximum external quantum efficiencies of 19%, which is comparable to the best doped OLEDs.

Keywords: electroluminescence; organic light-emitting diodes; thermally activated delayed fluorescence; undoped materials.