Repository logo
 

Mesitylated trityl radicals, a platform for doublet emission: symmetry breaking, charge-transfer states and conjugated polymers.

Accepted version
Peer-reviewed

No Thumbnail Available

Type

Article

Change log

Authors

Abstract

Neutral π-radicals have potential for use as light emitters in optoelectronic devices due to the absence of energetically low-lying non-emissive states. Here, we report a defect-free synthetic methodology via mesityl substitution at the para-positions of tris(2,4,6-trichlorophenyl)methyl radical. These materials reveal a number of novel optoelectronic properties. Firstly, mesityl substituted radicals show strongly enhanced photoluminescence arising from symmetry breaking in the excited state. Secondly, photoexcitation of thin films of 8 wt% radical in 4,4'-bis(carbazol-9-yl)-1,1'-biphenyl host matrix produces long lived (in the order of microseconds) intermolecular charge transfer states, following hole transfer to the host, that can show unexpectedly efficient red-shifted emission. Thirdly, covalent attachment of carbazole into the mesitylated radical gives very high photoluminescence yield of 93% in 4,4'-bis(carbazol-9-yl)-1,1'-biphenyl films and light-emitting diodes with maximum external quantum efficiency of 28% at a wavelength of 689 nm. Fourthly, a main-chain copolymer of the mesitylated radical and 9,9-dioctyl-9H-fluorene shows red-shifted emission beyond 800 nm.

Description

Keywords

3403 Macromolecular and Materials Chemistry, 34 Chemical Sciences, 40 Engineering, 51 Physical Sciences, 4016 Materials Engineering

Journal Title

Nat Commun

Conference Name

Journal ISSN

2041-1723
2041-1723

Volume Title

Publisher

Springer Science and Business Media LLC
Sponsorship
European Commission Horizon 2020 (H2020) Marie Sk?odowska-Curie actions (891167)
Engineering and Physical Sciences Research Council (EP/S003126/1)
European Commission Horizon 2020 (H2020) Marie Sk?odowska-Curie actions (886066)
Engineering and Physical Sciences Research Council (EP/S022953/1)
European Commission Horizon 2020 (H2020) Marie Sk?odowska-Curie actions (859752)
European Commission Horizon 2020 (H2020) ERC (101020167)