Molecules bearing separateπ-electron donor(D)and acceptor(A)groups that undergo face-to-face D/A interactions have been utilized to develop thermally activated delayed fluorescence(TADF)materials.Theseπ-stacked D/A ...Molecules bearing separateπ-electron donor(D)and acceptor(A)groups that undergo face-to-face D/A interactions have been utilized to develop thermally activated delayed fluorescence(TADF)materials.Theseπ-stacked D/A architectures are constructed on various scaffolds,which have either a long D/A distance or permitted conrotatory motion.Here,we develop a novel spiro-based scaffold with a short D/A distance and restricted circumvolution motions because of both the rigid spiro-scaffold and large rotation hindrance between the nearly coplanar D and A.We append different alkyl chains,which can modulate charge transfer and luminescence properties,at the nitrogen of the D moiety to develop four TADF molecules,which can modulate chargetransfer and luminescence properties.Because of the introduction of the solubilized alkyl chain,these molecules were used to fabricate solutionprocessed devices,among which a maximum external quantum efficiency of 18.9%was realized.By modulating interactions between the D/A building blocks,these TADF constructs exemplify that the alkyl side chains of TADF molecules,which used to be considered as solubilizing units,have vital impact on the optoelectronic properties and thus offer a new route to the design of solution-processable TADF emitters.展开更多
基金This project was also funded by the Collaborative Innovation Center of Suzhou Nano Science and Technology and by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)and the 111 Project.G.X.acknowledges the fundamental Research Funds for the Central Universities of China(no.2042019kf0234).
文摘Molecules bearing separateπ-electron donor(D)and acceptor(A)groups that undergo face-to-face D/A interactions have been utilized to develop thermally activated delayed fluorescence(TADF)materials.Theseπ-stacked D/A architectures are constructed on various scaffolds,which have either a long D/A distance or permitted conrotatory motion.Here,we develop a novel spiro-based scaffold with a short D/A distance and restricted circumvolution motions because of both the rigid spiro-scaffold and large rotation hindrance between the nearly coplanar D and A.We append different alkyl chains,which can modulate charge transfer and luminescence properties,at the nitrogen of the D moiety to develop four TADF molecules,which can modulate chargetransfer and luminescence properties.Because of the introduction of the solubilized alkyl chain,these molecules were used to fabricate solutionprocessed devices,among which a maximum external quantum efficiency of 18.9%was realized.By modulating interactions between the D/A building blocks,these TADF constructs exemplify that the alkyl side chains of TADF molecules,which used to be considered as solubilizing units,have vital impact on the optoelectronic properties and thus offer a new route to the design of solution-processable TADF emitters.
