Efficient Organic Light-Emitting Diode through Triplet Exciton Reharvesting by Employing Blended Electron Donor and Acceptor as the Emissive Layer

Lu Zhang; Chao Cai; King Fai Li; Hoi Lam Tam; Kin Long Chan; Kok Wai Cheah

doi:10.1021/acsami.5b05597

Efficient Organic Light-Emitting Diode through Triplet Exciton Reharvesting by Employing Blended Electron Donor and Acceptor as the Emissive Layer

ACS Appl Mater Interfaces. 2015 Nov 18;7(45):24983-6. doi: 10.1021/acsami.5b05597. Epub 2015 Nov 4.

Authors

Lu Zhang¹, Chao Cai¹, King Fai Li¹, Hoi Lam Tam¹, Kin Long Chan¹, Kok Wai Cheah¹

Affiliation

¹ Department of Physics and Institute of Advanced Materials, Hong Kong Baptist University , Kowloon Tong, Hong Kong SAR, China.

PMID: 26529382
DOI: 10.1021/acsami.5b05597

Abstract

A blended bimolecular exciplex formation was demonstrated between two individual donor and acceptor molecules, which are tris(4-carbazoyl-9-ylphenyl)amine (TCTA) and 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine (Tm3PyBPZ). The photoluminescence spectrum of the exciplex in the solid state showed an emission with a peak around 514 nm (∼2.49 eV). By applying this exciplex as an emitting layer, a highly efficient all-fluorescent organic lighting emitting diode with maximum efficiencies of 13.1% and 53.4 lm/W can be realized under an extremely low turn-on voltage of only 2.4 V. The thermally activated delayed fluorescence (TADF) process is believed to be responsible for the excellent device performance.

Keywords: intermolecular exciplex; organic light-emitting diode (OLED); thermally activated delayed fluorescence (TADF); triplet exciton reharvesting; weak coupled donor and acceptor.

Publication types

Research Support, Non-U.S. Gov't