Phenoxazine-Dibenzothiophene Sulfoximine Emitters Featuring Both Thermally Activated Delayed Fluorescence and Aggregation Induced Emission

Abstract

In this work, we demonstrate dibenzothiophene sulfoximine derivatives as building blocks for constructing emitters featuring both thermally activated delayed fluorescent (TADF) and aggregation-induced emission (AIE) properties, with multiple advantages including high chemical and thermal stability, facile functionalization, as well as tunable electron-accepting ability. A series of phenoxazine-dibenzothiophene sulfoximine structured TADF emitters were successfully synthesized and their photophysical and electroluminescent properties were evaluated. The electroluminescence devices based on these emitters displayed diverse emissions from yellow to orange and reached external quantum efficiencies (EQEs) of 5.8% with 16.7% efficiency roll-off at a high brightness of 1000 cd·m−2.

Tuning Photophysical Properties via Positional Isomerization of the Pyridine Ring in Donor–Acceptor-Structured Aggregation-Induced Emission Luminogens Based on Phenylmethylene Pyridineacetonitrile Derivatives

“…Overall, the enhanced emission intensity and the extended fluorescence lifetime of the non-doped films indicates that the formation of the aggregate state may affect the decay pathway of the excited state, i.e., suppressing the nonradiative decay [ 45 , 46 , 47 ]. The different fluorescence lifetimes and quantum yields among the isomers were probably derived from the varied molecular configurations and conjugations in the solid state due to the substitutional position of the pyridine ring [ 48 ]. For o -DBCNPy , the strongest emission intensity might be derived from a more planarized molecular configuration led by the interaction between the ortho -nitrogen atom and the vinyl hydrogen atom (-CH=C-).…”

On the Road Toward More Efficient Biocompatible Two‐Photon Excitable Fluorophores

“…In this work, we proposed to study a new family of quadrupolar dyes by enriching previous cores, to increase their two‐photon absorption properties. Recently, phenoxazine, acridane, phenazasiline and phenothiazine have been used as very efficient donor cores in material chemistry [22–26] . However, these cores have never been extensively studied for their nonlinear properties and we decided to explore their potential to be used as donor cores for two‐photon absorption (Figure 1).…”

“…Recently, phenoxazine, acridane, phenazasiline and phenothiazine have been used as very efficient donor cores in material chemistry. [22][23][24][25][26] However, these cores have never been extensively studied for their nonlinear properties and we decided to explore their potential to be used as donor cores for twophoton absorption (Figure 1).…”