Date：2017-11-22 |
Views：1840 |
【Academic writing Sharing 20171121】 |
Pure Organic Emitter with Simultaneous Thermally Activated Delayed Fluorescence and Room-Temperature Phosphorescence: Thermal-Controlled Triplet Recycling Channels
Article excerpt is from:Ling Yu, Zhongbin Wu, Cheng Zhong, Guohua Xie, Zece Zhu, Dongge Ma,and Chuluo Yang
Adv. Optical Mater. 2017, 1700588
A new route to utilize the triplet excitons by simultaneous thermally activated
delayed fluorescence (TADF) and phosphorescence is demonstrated for a new
quinoxaline/phenoxazine hybrid emitter. Moreover, the two triplet recycling
channels are thermally controlled, and a clear threshold temperature of
170 K is observed. Below the threshold temperature, direct triplet radiation
(phosphorescence) is the dominant process. In contrast, the channel of
upconversion through intersystem crossing is activated above the threshold
and the resulting TADF gradually becomes the predominant process. By
using the new compound as emitter in organic light-emitting diodes, a high
external quantum efficiency of 16.8% is far beyond the theoretical limit of the
traditional fluorescent emitters.
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