Doublet-emissive materials for organic light-emitting diodes: exciton formation and emission processes

Abstract

This tutorial review introduces the emission mechanism, recent research, advantages, challenge and future outlook of novel emissive materials with the doublet state and their application in OLEDs.

Recent advances in highly-efficient near infrared OLED emitters

“…For more in-depth details on doublet states and emission mechanisms, we suggest ref. 150–153. To sum up, radicals eliminate the problem of 'dark' triplet formation observed in closed shell molecules and present new avenues for the development of OLEDs with IQE up to 100%.…”

Rationalizing the carborane versus phenyl-driven luminescence in related dicarboxylic ligands and their antenna effect for their Eu3+ and Tb3+ metal–organic frameworks: a combined experimental and computational study

“…Luminescent materials have attracted significant attention due to their wide-ranging applications in fields such as optoelectronics, photonics, and bioimaging. 1–5 The ability to control and manipulate the luminescent properties of materials is of utmost importance for designing advanced functional materials with tailored properties. In this context, the choice of molecular scaffolds as ligands plays a crucial role in determining the luminescent behavior of a material.…”

Steric Control of Luminescence in Phenyl-Substituted Trityl Radicals

“…Neutral π-radicals with an emissive doublet excited state (D 1 ) are of interest for applications in photonics and light-emitting devices − and magnetically and optically addressable quantum systems − because of the absence of energetically low-lying nonemissive states in these materials. Chlorinated triphenylmethyl (trityl) radicals like tris­(2,4,6-trichlorophenyl)­methyl (TTM) are among the most studied spin doublet systems largely because of their remarkable stability up to years in ambient air. , Previously, trityl radicals had been classified as dark with photoluminescence quantum efficiencies (PLQEs) not higher than few percent. − This is because their alternant symmetry structure gives rise to an energetically symmetric splitting of occupied and unoccupied molecular orbitals with a distinction that only their sign is opposite relative to the nonbonding, singly occupied molecular orbital (SOMO), as illustrated in Figure .…”