Search

Your search keyword '"Penfold T.J."' showing total 11 results
Start Over Author "Penfold T.J."
11 results on '"Penfold T.J."'

2. Atomic-scale observation of solvent reorganization influencing photoinduced structural dynamics in a copper complex photosensitizer

Author

Katayama T., Choi T.-K., Khakhulin D., Dohn A.O., Milne C.J., Vankó G., Németh Z., Lima F.A., Szlachetko J., Sato T., Nozawa S., Adachi S.-I., Yabashi M., Penfold T.J., Gawelda W., Levi G., Katayama T., Choi T.-K., Khakhulin D., Dohn A.O., Milne C.J., Vankó G., Németh Z., Lima F.A., Szlachetko J., Sato T., Nozawa S., Adachi S.-I., Yabashi M., Penfold T.J., Gawelda W., and Levi G.

Published
2023

8. Triazatruxene : a rigid central donor unit for a D-A3 thermally activated delayed fluorescence material exhibiting sub-microsecond reverse intersystem crossing and unity quantum yield via multiple singlet-triplet state pairs

Author

dos Santos, P.L., Ward, J.S., Congrave, D.G., Batsanov, A.S., Eng, J., Stacey, J.E., Penfold, T.J., Monkman, A.P., and Bryce, M.R.

Abstract

By inverting the common structural motif of thermally activated delayed fluorescence materials to a rigid donor core and multiple peripheral acceptors, reverse intersystem crossing (rISC) rates are demonstrated in an organic material that enables utilization of triplet excited states at faster rates than Ir‐based phosphorescent materials. A combination of the inverted structure and multiple donor–acceptor interactions yields up to 30 vibronically coupled singlet and triplet states within 0.2 eV that are involved in rISC. This gives a significant enhancement to the rISC rate, leading to delayed fluorescence decay times as low as 103.9 ns. This new material also has an emission quantum yield ≈1 and a very small singlet–triplet gap. This work shows that it is possible to achieve both high photoluminescence quantum yield and fast rISC in the same molecule. Green organic light‐emitting diode devices with external quantum efficiency >30% are demonstrated at 76 cd m−2.

Published
2018

11. Ultrafast dynamics of the S1 excited state of benzene

Author

Parker, D.S.N., Minns, R.S., Penfold, T.J., Worth, G.A., and Fielding, H.H.

Subjects
*EXCITED state chemistry, *BENZENE, *MOLECULAR dynamics, *PICOSECOND pulses, *PHOTOELECTRON spectroscopy, *QUANTUM theory
Abstract

Abstract: We investigate the ultrafast intramolecular dynamics of electronically and vibrationally excited benzene using time-resolved photoelectron spectroscopy and quantum dynamics simulations. In addition to an ultrafast initial decay, we observe an oscillation between two states. We interpret this data in terms of excited state population moving away from the Franck–Condon region towards the singlet–singlet conical intersection with the ground-state, where ultrafast intersystem crossing from the initially populated singlet state to an optically dark triplet state is enhanced. Our results challenge the currently accepted view that intramolecular processes in hydrocarbons which involve a change of spin are negligibly slow. [Copyright &y& Elsevier]

Published
2009
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results