Achieving highly efficient narrowband sky-blue electroluminescence with alleviated efficiency roll-off by molecular-structure regulation and device-configuration optimization

Abstract

Multiple resonance effect induced thermally activated delayed fluorescence (MR-TADF) materials that can exhibit high luminous efficiency and color purity have aroused tremendous attention owing to their promising applications in wide...

Organoboron-based multiple-resonance emitters: synthesis, structure–property correlations, and prospects

“…11 and Table 11). 155–165 In most cases, the para -positions of the carbazole nitrogen atoms were pre-functionalised and used in the S N Ar-based one-pot borylation protocol. The highly functionalised carbazolyl subunits ( e.g.…”

Recent progress and prospects of fluorescent materials based on narrow emission

“…10j). 90 Incorporating sterically hindered groups at the periphery of the primitive MR core facilitated the weakening of contact between adjacent emitters, thereby reducing the occurrence of bimolecular events involving triplet excitons. The emitters showed sky-blue PL/narrow FWHM of 474/24 nm for DCzB , 481/22 nm for D t CzB , 477/19 nm for Tip-D t CzB and 470/21 nm for t DPA-D t CzB .…”

Sulfide, Sulfoxide, and Sulfone Substitution: Electron Structure Modulation from Para‐D‐π‐B to Para‐A‐π‐B in Multiple‐Resonance Emitters with Narrowband Emission and High Color Purity

“…In addition, BN(p)SCH 3 had the biggest reverse intersystem crossing rate constants (k RISC ) of 6.4 × 10 4 s −1 owing to the small ΔE ST value of 0.12 eV, higher than 3.0 × 10 4 s −1 for BN(p)SOCH 3 and 3.5 × 10 4 s −1 for BN(p)SO 2 CH 3 . [27] Moreover, according to Fermi's golden rule, [28] the enlarged SOC constants of S 1 -T 2 and S 1 -T 3 transitions in BN(p)SCH 3 are beneficial to obtain high k RISC . We also noticed that the k RISC of BN(p)SO 2 CH 3 was only 3.5 × 10 4 s −1 , which may suffer from its large ΔE ST and the low emission contribution of triplet excitons due to the low ratio of delay component of 6%.…”