Jump to main content
Jump to site search


Systematic control of the rate of singlet fission within 6,13-diphenylpentacene aggregates with PbS quantum dot templates

Author affiliations

Abstract

Lead chalcogenide quantum dots (QDs) are promising acceptors for photovoltaic devices that harness the singlet fission (SF) mechanism. The rate of singlet fission of polyacenes in the presence of QDs is a critical parameter in determining the performance of such devices. The present study demonstrates that the rates of SF in a pentacene derivative, 6,13-diphenylanthracene (DPP), are modulated by forming coaggregates with PbS QDs in aqueous dispersions. PbS QDs generally accelerate SF within DPP aggregates, and the extent of acceleration depends on the size of the QD. The average rate of SF increases from 0.074 ps−1 for DPP-only aggregates to 0.37 ps−1 within DPP-D co-aggregates for QDs with radius 2.2 nm, whereas co-aggregation with the smallest (r = 1.6 nm) and largest (r = 2.7 nm) QDs we tried only slightly change the SF rate. The rate variation is associated with (i) the density of surface ligands, which is influenced by the faceting of the PbS surface, and (ii) the local dielectric constant for DPP. To accelerate SF, the ligands should be dense enough to provide sufficient affinity for DPP aggregates and effectively perturb the perpendicular alignment of DPP monomers within aggregates to increase the intermolecular coupling that promotes SF, but should not be too dense so as to form a low dielectric environment that disfavors SF. The study suggests that it is critical to consider the influence of the microenvironment of the QD surface on photophysical processes when fabricating QD/organic hybrid devices.

Graphical abstract: Systematic control of the rate of singlet fission within 6,13-diphenylpentacene aggregates with PbS quantum dot templates

Back to tab navigation

Supplementary files

Publication details

The article was received on 24 Oct 2018, accepted on 20 Dec 2018 and first published on 20 Dec 2018


Article type: Paper
DOI: 10.1039/C8FD00157J
Citation: Faraday Discuss., 2019, Advance Article

  •   Request permissions

    Systematic control of the rate of singlet fission within 6,13-diphenylpentacene aggregates with PbS quantum dot templates

    C. Wang, M. S. Kodaimati, S. Lian and E. A. Weiss, Faraday Discuss., 2019, Advance Article , DOI: 10.1039/C8FD00157J

Search articles by author

Spotlight

Advertisements