In this study, two polymeric host materials, P(NmCP) and P(mCP), were synthesized, and high-performing sky-blue and green thermally activated delayed fluorescence organic light-emitting diodes (TADF-OLEDs) were achieved. The simple structure polymer host was designed by inserting a pyridine group into the core of P(NmCP) and an electron-donating phenyl group into the core of P(mCP). The two polymeric hosts exhibited high triplet energies (T1 = 3.04 eV for P(NmCP) and 3.05 eV for P(mCP)), which were sufficiently high to realize blue and green TADF-OLEDs. In brief, solution-processed OLEDs with an emissive layer bearing P(NmCP) as a bipolar electron host exhibited remarkable performance with a maximum current efficiency (CE), power efficiency (PE), and external quantum efficiency (EQE) of 70.36 cd A-1, 63.15 lm W-1, and 20.07%, respectively, in the green-emitting device. In the blue-emitting device, we obtained a maximum CE, PE, and EQE of 27.13 cd A-1, 22.30 lm W-1, and 10.70%, respectively. The polymer design with such a high T1 value is believed to be the cornerstone for implementing high-performance TADF-OLEDs via solution processing in the future. This journal is
Bibliographical noteFunding Information:
The authors acknowledge the financial support from the National Research Foundation of Korea (NRF2019R1A2C2002647, NRF2019R1A6A1A11044070) and D. H. Choi particularly thanks for the support from LG Display Co. Limited (Q1927051, 2020).
© The Royal Society of Chemistry.
ASJC Scopus subject areas
- Materials Chemistry