Combining Benzotriazole and Benzodithiophene Host Units in Host-Guest Polymers for Efficient and Stable Near-Infrared Emission from Light-Emitting Electrochemical Cells
Journal article, 2019

A set of host-guest copolymers with alternating benzodithiophene and benzotriazole (BTz) derivatives as host units and 4,7-bis(5-bromothiophen-2-yl)-benzo[c][1,2,5]thiadiazole as the minority guest are synthesized, characterized, and evaluated for applications. A light-emitting electrochemical cell (LEC) comprising such a host-guest copolymer delivers fast-response near-infrared (NIR) emission peaked at 723 nm with a high radiance of 169 mu W cm(-2) at a low drive voltage of 3.6 V. The NIR-LEC also features good stability, as the peak NIR output only drops by 8% after 350 h of continuous operation. It is, however, found that the LEC performance is highly sensitive to the detailed chemical structure of the host backbone, and that the addition of electron-donating thiophene bridging units onto the BTz unit is highly positive while the inclusion of fluorine atoms results in a drastically lowered performance, presumably because of the emergence of hydrogen bonding within the active material.

near-infrared emission light-emitting electrochemical cells

conjugated polymers

host-guest copolymers

Author

Wenjing Xiong

Changzhou University

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Shi Tang

Umeå University

Petri Henrik Murto

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Weiguo Zhu

Changzhou University

Xiangtan University

Ludvig Edman

Umeå University

Ergang Wang

Chalmers, Chemistry and Chemical Engineering, Applied Chemistry

Advanced Optical Materials

2195-1071 (eISSN)

Vol. 7 15 1900280

Subject Categories

Inorganic Chemistry

Other Chemical Engineering

Other Chemistry Topics

DOI

10.1002/adom.201900280

More information

Latest update

11/11/2019