Article pubs.acs.org/JPCC
Morphological Evolution and Singlet Fission in Aqueous Suspensions of TIPS-Pentacene Nanoparticles Murad J. Y. Tayebjee,*,† Kyra N. Schwarz,‡ Rowan W. MacQueen,§ Miroslav Dvořaḱ ,§,⊥ Andrew W. C. Lam,∥ Kenneth P. Ghiggino,‡ Dane R. McCamey,∥ Timothy W. Schmidt,# and Gavin J. Conibeer† †
School School § School ∥ School # School ‡
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Photovoltaic and Renewable Energy Engineering, UNSW, Sydney, NSW 2052, Australia Chemistry, The University of Melbourne, Parkville, Victoria 3010, Australia Chemistry, The University of Sydney, Sydney, NSW 2006, Australia Physics, UNSW, Sydney, NSW 2052, Australia Chemistry, UNSW, Sydney, NSW 2052, Australia
S Supporting Information *
ABSTRACT: We report the observation of singlet fission in aqueous suspensions of 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn) nanoparticles (NPs) synthesized using the reprecipitation method. By altering the synthesis conditions we are able to fabricate NPs which evolve from a system of poorly coupled to highly coupled chromophores. This morphological evolution can also be suppressed for a period of several months. Absorption spectra confirm that the particles evolve over time, displaying increased intermolecular interaction, if the initial reaction conditions seeded a polycrystalline sample. We correlate these differences in morphologies to different rates of singlet state decay, where higher intermolecular interaction drives a more rapid rate of decay. Ultrafast time-resolved photoluminescence spectroscopy confirms a short first excited singlet state lifetime (
