Ancillary ligand effect with methyl and t-butyl for deep blue and high EQE blue phosphorescent organic light-emitting diodes

Investigation of the Relationship between Quantum Yield, Charge-Transfer State, and Structure of the Ligands in Red-Emitting Heteroleptic Iridium(III) Complexes

“…Previous researchers associated 3 MLCT states with phosphorescence and triplet metal-centered ( 3 MC) states with nonradiative decay to the ground state (S 0 ). In other words, the primary phosphorescent emitter quenching pathway is generally thought to originate from the conversion from 3 MLCT to 3 MC state. − Therefore, a smaller energy gap between these two states would result in better access to the nonradiative decay state. The energy gap between the T 1 ( 3 MLCT) and T 2 ( 3 MC) states of Red-pq and Red-piq is 8.40 kcal/mol and 15.09 kcal/mol, respectively.…”

Highly efficient platinum(ii) complexes overcoming Pt–Pt interactions and their applications in organic light-emitting diodes

“…1–12 Over recent decades, phosphorescent organic light-emitting devices (PhOLEDs) have gained widespread utilization in full-color displays due to their ability to harness both singlet and triplet excitons. 1,7,10,12–19 However, a notable challenge arises with Pt( ii ) complexes when integrated into solid-state films, attributed to undesired spectral alterations resulting from robust Pt–Pt interactions induced by the parallel alignment of Pt( ii ) complexes. 4,20–23 This phenomenon leads to broadened and red-shifted emission spectra, ultimately compromising the luminescence performance within solid films.…”