| Title |
Not the sum of their parts: understanding multi-donor interactions in symmetric and asymmetric TADF emitters / |
| Authors |
Danos, Andrew ; Gudeika, Dalius ; Kukhta, Nadzeya A ; Lygaitis, Ramunas ; Colella, Marco ; Higginbotham, Heather F ; Bismillah, Aisha N ; McGonigal, Paul R ; Grazulevicius, Juozas Vidas ; Monkman, Andrew P |
| DOI |
10.1039/d1tc04171a |
| Full Text |
|
| Is Part of |
Journal of materials chemistry C.. Cambridge : Royal society of chemistry. 2022, vol. 10, iss. 12, p. 4737-4747.. ISSN 2050-7526. eISSN 2050-7534 |
| Keywords [eng] |
activated delayed fluorescence ; aggregation-induced emission ; light-emitting-diodes ; triplet-states ; molecule ; efficiency ; strategy ; singlet ; acceptors ; design |
| Abstract [eng] |
A pair of thermally activated delayed fluorescence (TADF) emitters with symmetric and asymmetric D-A-D structure are investigated. Despite displaying near-identical photoluminescence spectrum and quantum yields, the symmetric material possesses significantly better delayed fluorescence characteristics and OLED performance. Building on a previous study of analogous D-A materials we are able to explain these differences in terms of different strengths of electronic interactions between the two donor units. This interaction lowers the energy of the TADF-active triplet state in the asymmetric molecule, increasing its singlet-triplet energy gap and leading to worse performance. This result therefore demonstrates a new strategy to selectively control the triplet states of TADF molecules, in contrast to established control of singlet states using host environment. These results also show that multi-donor TADF emitters cannot be understood simply as the sum of their isolated parts; these parts have different electronic interactions depending on their relative positions, even when there is no scope for steric interaction. |
| Published |
Cambridge : Royal society of chemistry |
| Type |
Journal article |
| Language |
English |
| Publication date |
2022 |
| CC license |
|
