An ideal universal host for highly efficient full-color, white phosphorescent and TADF OLEDs with a simple and unified structure

Abstract

Via employing a unique universal host, highly efficient full-color, white phosphorescent and TADF OLEDs were achieved with a simple and unified structure.

New Mixed‐C^N Ligand Tris‐Cyclometalated IrIII Complexes for Highly‐Efficient Green Organic Light‐Emitting Diodes with Low Efficiency Roll‐Off

“…On each occasion D3 and D4 out‐performed D2 and D5 which clearly points to a significant benefit of the mixed‐ C ^ N ligand structures. These high efficiencies of D3 and D4 with a simple HTL/EML/ETL device structure and commercially available host and transport layer materials, are comparable with the highest reported levels of PhOLEDs employing the classical homoleptic or heteroleptic Ir complexes Ir(ppy) 3 ( 2 ) or (ppy) 2 Ir(acac) ( 1 ), respectively, using more complicated and refined device structures, and/or non‐commercial host or co‐host materials . More significantly, the direct comparison of devices D1 – D6 in the present work convincingly demonstrates that high‐level EL performance of the classical homoleptic and heteroleptic phosphors can be maintained, and even slightly enhanced, with tris‐cyclometalated Ir complexes with mixed‐ C ^ N ligands.…”

Molecular Engineering of Host Materials for High‐Performance Phosphorescent OLEDs: Zig‐Zag Conformation with 3D Gridding Packing Mode Facilitating Charge Balance and Quench Suppression

“…Among these co‐deposited films, m ‐BPySCz:FIrpic exhibited the largest radiative rate constant ( k r ) of 8.19 × 10 5 s −1 and small nonradiative rate constant ( k nr ) of 0.64 × 10 5 s −1 , hence the highest ratio of k r / k nr (12.69) was realized. Even in comparison with many reported blue PhOLEDs containing single host in literatures (Table S4, Supporting Information), the present m ‐BPySCz‐hosted device B3 exhibited higher k r / k nr of 12.69, which can explain the m ‐BPySCz‐hosted device exhibited extraordinarily low efficiency roll‐off at high brightness region. Evidently the transient PL decay results well account for the device performance and confirm the remarkable exciton quenching suppression effect of m ‐BpySCz caused by its unique 3D gridding packing style.…”

Evolution of pure hydrocarbon hosts: simpler structure, higher performance and universal application in RGB phosphorescent organic light-emitting diodes

“…As summarized in Table S16 (ESI), † some of the bestperformance universal host materials for RGB OLEDs reported to date in the literature are designed with heteroatoms and only a few of them can achieve high EQEs over 20% in all the visible regions. 5,9,14,[41][42][43][44][45][46][47][48][49] The results suggest that PHCs can exceed the best universal hosts constructed with conventional heteroatom design principles.…”