The study of organic light-emitting diode (OLED) has become the cutting edge in both academia and industrial community. Because of great potentials in areas as 3D displays, circularly polarized OLEDs (CP-OLEDs) have received more and more attentions during the past several years. Due to the difficulty in developing chiral luminescent materials, the fabrication of CP-OLEDs with white emission is regarded as a challenge in this area.
Based on their previous progress for a chiral blue TADF material (R/S-OSFSO,Angew. Chem. Int. Ed. 2021, 60, 8435), Zheng’s group synthesized a novel chiral yellow TADF material (R/S-SPOCN). R/S-OSFSO exhibits blue emission centered at 470 nm with CIE of (0.17, 0.24) in toluene solution and R/S-SPOCN shows yellow emission centered at 581 nm with CIE of (0.50,0.49) in toluene solution. Both of OSFSO and SPOCN displayed TADF property and circularly polarized luminescence (CPL) property, |gPL| factors were detected to be 1.4×10-3 and 1.6×10-3 for R/S-OSFSO and R/S-SPOCN in toluene solutions, respectively.
Based on R/S-OSFSO and R/S-SPOCN, white CP-OLEDs with double emissive layers were fabricated. The devices showed stable warm-white emission with CIE of (0.35, 0.46) and CRI of 69. White CP-OLEDs also exhibited decent performances with a luminance of 15700 cd/m2, a maximum external quantum efficiency up to 21.6% and symmetrical CPEL signals with |gEL| around 3.0×10-3. This is the first report of white CP-OLEDs that can harvest both singlet and triplet excitons, which provided a new strategy towards efficient white CP-OLEDs.
This work was published in Angew. Chem. Int. Ed. (2022, DOI: 10.1002/anie.202200290) recently, Prof. You-Xuan Zheng is the corresponding author, Ph.D. candidates Yi-Pin Zhang is the first author. Prof. Jing-Lin Zuo, Prof. Yi Pan and Prof.Yi Wang gave precious advice to this work.
Online link:https://onlinelibrary.wiley.com/doi/10.1002/anie.202200290