A comparative study of two multi-resonance TADF analogous materials integrating chalcogen atoms of different periods

Abstract

Two multi-resonance (MR) thermally activated delayed fluorescence (TADF) analogous materials, BNCzPXZ and BNCzPTZ, respectively integrating oxygen and sulfur elements were compared to in-depth investigate the influences of introducing elements of...

Constructing Multiresonance Thermally Activated Delayed Fluorescence Emitters for Organic LEDs: A Computational Investigation

“…We chose a set of experimentally reported well-known MR compounds (B1–B5) for validation (see Figure ). ,,,, The vertical T 1 → S 1 energy difference computed at the DLPNO-STEOM-CCSD/Def2-SVP level of theory was compared against the experimental Δ E ST values. The computed values are given in Table .…”

Recent progress and prospects of fluorescent materials based on narrow emission

“…12k) by replacing carbazole with 3,6-di- tert -butyl-9 H -carbazole. 100,101 Similarly, the best performance was obtained for the B,N-Se-based OLEDs with a narrowband emission peak at 506 nm, an FWHM of 45 nm, CIE color coordinates of (0.15, 0.62) and EQE max of 32.6%. In particular, the device exhibited an ultralow efficiency roll-off with EQE values remaining as high as 32.2% and 24.0% at 1000 and 10 000 cd m −2 , respectively.…”

“…12 (a-l) Chemical structures of emitters discussed in Section 3.2.2. 27,30,[91][92][93][94][95][96][97][98][99][100][101][102] This journal is © The Royal Society of Chemistry 2023 (94%) and BSBS-Z (93%) exhibited higher PLQYs compared to oxygen-doped BOBO-Z (76%). The devices based on BOBO-Z, BOBS-Z, and BSBS-Z realized narrowband blue emission with FWHMs of 18, 23 and 22 nm, l EL of 445, 456 and 463 nm, and CIE color coordinates of (0.15, 0.04), (0.14, 0.06) and (0.13, 0.08), respectively.…”

A review of fused-ring carbazole derivatives as emitter and/or host materials in organic light emitting diode (OLED) applications

“…There is a very recent suggestion that the similar size of oxygen and carbon atoms may optimise narrowband MR emission compared to a sulfur analogue, as the larger sulfur atom can reduce both the π-conjugation and the molecular rigidity, thereby increasing geometrical relaxation energies which broaden the FWHM. 170 Also, there is evidence that device operational lifetimes can be adversely affected by the heavier chalcogen atoms, 171 perhaps due to the higher chemical reactivity of C-X bonds (X = S, Se), although this is not the case with the CzBO , CzBS and CzBSe series (Fig. 41a).…”