A computational scheme for evaluating the phosphorescence quantum efficiency: applied to blue-emitting tetradentate Pt(ii) complexes

Abstract

Phosphorescent organic light-emitting diodes (PhOLEDs) are leading candidates for displays or lighting technologies. Recently, blue phosphorescent tetradentate Pt(II) complexes have been attracted extensive attentions due to their highly phosphorescent quantum...

Fused 6/5/6 Metallocycle-Based Tetradentate Pt(II) Emitters for Efficient Green Phosphorescent OLEDs

“…These Pt(II) emitters typically have the highest occupied molecular orbital (HOMO) distributions on two phenyl (Ph) rings and the Pt moiety for blue emitters and a phenyl-Het moiety for green and red emitters. [27][28][29][30][31][32][33][34][35][36]47,[50][51][52][53][54][55][56]60 Type II tetradentate Pt(II) emitters contain three linking atoms with an extremely distorted 6/6/6 metallocycle where the HOMO is on the Ph-O-Ph and Pt moiety. 61,66 Type III and type IV use phenolate ligands with one or no linking atoms, where the HOMO is on the electronrich phenolate and Pt moieties.…”

The mechanism of intramolecular halogen bonding enhanced the quantum efficiency of ultralong organic phosphorescence in the aggregated state

“…The non-radiative decay process includes two paths, one is the ISC process within the Harmonic region and the other is the process via the T 1 /S 0 minimum energy crossing point (MECP) beyond the Harmonic region. 65,66 In this work, we focus on the first path of the non-radiative decay process and corresponding research on the MECP will be presented in our later work. According to eqn (9), the non-radiative rate constant is mainly controlled by three key parameters: adiabatic excitation energy, reorganization energy and spin–orbit coupling constant between T 1 and S 0 .…”

Investigate the Relationship between Structure and Triplet Potential Energy Surface to Control the Phosphorescence Quantum Yield of Platinum(II) Complex: A Theoretical Investigation

“…In popular phosphorescent materials, for example, Pt­(II) and Ir­(III) complexes, the radiative decay rates depend on the percentage of metal-to-ligand charge transfer ( 3 MLCT) because the phosphoresce is caused by the strong spin–orbital coupling (SOC) originating from the heavy atoms (Pt­(II) and Ir­(III)). − Compared with the radiative decay rates, the nonradiative decay rates can be affected by more factors, which include the temperature-independent nonradiative decay process and the thermally activated nonradiative photo-deactivation pathway. The temperature-independent nonradiative decay process is closely related to the triplet energy, the Huang–Rhys factors ( Si ) used to elucidate the molecular rigidity, and the SOC matrix element between T 1 (lowest-lying triplet excited state) and S 0 (ground state). , In the case of the thermally activated nonradiative photo-deactivation pathway, the potential energy surface of triplet excited states should be constructed, that is, the 3 ES (emission state) → TS­( 3 ES/ 3 MC, transition state) → 3 MC (metal-centered excited state) → minimum-energy crossing point (MECP) conversion. − …”