Thermally activated delayed fluorescence (TADF). Rational design of fluorophores using a joined synthetic and computational chemistry approach (R-8178)

In recent years, a number of organic semiconducting materials have been developed to exploit the new light emission principle of Thermally Activated Delayed Fluorescence (TADF). This concept enables to realize unique optical and electronic properties arising from the efficient interconversion between the lowest singlet (S1) and triplet (T1) excited states of organic fluorophores. As a result, TADF-based organic light-emitting diodes, oxygen and temperature sensors show significantly upgraded device performances, comparable to those provided by traditional rare metal complexes. To realize efficient TADF, organic luminophores require a very small energy difference (delta EST) between their S1 and T1 excited states, which enhances the T1->S1 reverse intersystem crossing rate. Such excited state equilibration is attainable by intramolecular charge transfer within systems containing spatially separated donor and acceptor moieties. The critical point of this molecular design is the combination of a small delta EST (kleiner of gelijk aan 100 meV) with a reasonable radiative decay rate (>106 s-1) to overcome competitive non-radiative pathways, leading to highly luminescent materials. In the presented project, advanced TADF materials will be designed, synthesized and characterized by a rational approach combining the highly complementary computational and synthetic materials expertise provided by the partner groups. Particular emphasis will also be put on the application of the TADF concept in bio-imaging.

Keywords:Thermally activated delayed fluorescence (TADF)

Disciplines:Organic chemistry

Project type:Collaboration project