Premium
Donor–Acceptor Shape Matching Drives Performance in Photovoltaics
Author(s) -
Schiros Theanne,
Kladnik Gregor,
Prezzi Deborah,
Ferretti Andrea,
Olivieri Giorgia,
Cossaro Albano,
Floreano Luca,
Verdini Alberto,
Schenck Christine,
Cox Marshall,
Gorodetsky Alon A.,
Plunkett Kyle,
Delongchamp Dean,
Nuckolls Colin,
Morgante Alberto,
Cvetko Dean,
Kymissis Ioannis
Publication year - 2013
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201201125
Subject(s) - materials science , organic solar cell , acceptor , heterojunction , photovoltaics , optoelectronics , exciton , density functional theory , dissociation (chemistry) , photovoltaic system , organic semiconductor , chemical physics , nanotechnology , polymer , computational chemistry , chemistry , physics , ecology , biology , condensed matter physics , quantum mechanics , composite material
While the demonstrated power conversion efficiency of organic photovoltaics (OPVs) now exceeds 10%, new design rules are required to tailor interfaces at the molecular level for optimal exciton dissociation and charge transport in higher efficiency devices. We show that molecular shape‐complementarity between donors and acceptors can drive performance in OPV devices. Using core hole clock (CHC) X‐ray spectroscopy and density functional theory (DFT), we compare the electronic coupling, assembly, and charge transfer rates at the interface between C 60 acceptors and flat‐ or contorted‐hexabenzocorone (HBC) donors. The HBC donors have similar optoelectronic properties but differ in molecular contortion and shape matching to the fullerene acceptors. We show that shape‐complementarity drives self‐assembly of an intermixed morphology with a donor/acceptor (D/A) ball‐and‐socket interface, which enables faster electron transfer from HBC to C 60 . The supramolecular assembly and faster electron transfer rates in the shape complementary heterojunction lead to a larger active volume and enhanced exciton dissociation rate. This work provides fundamental mechanistic insights on the improved efficiency of organic photovoltaic devices that incorporate these concave/convex D/A materials.