In:
Journal of Materials Chemistry C, Royal Society of Chemistry (RSC)
Abstract:
In order to develop novel thermally activated delayed fluorescence (TADF) materials based on pyrenopyrazine and deeply study structure-property relationship, two emitters of PyPzCN-TPA2 and PyQlCN-TPA2 were designed and synthesized by alternating pyreno- pyrazine-9,10-dicarbonitrile (PyPzCN) and pyrenoquinoxaline-10,11-dicarbonitrile (PyQl -CN) as rigid electron-deficient skeleton, as well as triphenylamine (TPA) as electron-rich unit anchored at the K-region of pyrene, respectively. The effect of the rigid electron-deficient skeleton and electron-rich TPA unit on photophysical and electroluminescent (EL) were primarily studied. The extending rigid electron-deficient skeleton made PyQlCN-TPA2 exhibit red-shifted emission at 658 nm in toluene and 840 nm in its neat film. The appending electron-rich TPA unit at the K-region makes both emitters exhibit large steric hindrance with a torsion angle more than 70°, which result in a small ΔEST about 0.032 eV and a high kRISC about 1.6 ~ 4.7 ×105 s−1. As a result, the solution-processing PyPzCN-TPA2 and PyQlCN-TPA2 doped OLEDs simultaneously exhibit a high EQE of 9.30% and 8.94% with an emission peak at 588 and 630 nm, respectively. This is first sample of high-efficiency red-emitting pyrene-based TADF material by extending rigid electron-deficient skeleton from pyrenopyrazine to pyrenoquinoxaline and appending electron-rich unit at the K-region obtained in the solution-processed OLEDs.
Type of Medium:
Online Resource
ISSN:
2050-7526
,
2050-7534
Language:
English
Publisher:
Royal Society of Chemistry (RSC)
Publication Date:
2023
detail.hit.zdb_id:
2702245-6
Permalink