Open AccessStrong light-matter coupling for reduced photon energy losses in organic photovoltaics
Author(s) -
Vasileios C. Nikolis,
Andreas Mischok,
Bernhard Siegmund,
Jonas Kublitski,
Xiangkun Jia,
Johannes Benduhn,
Ulrich Hörmann,
Dieter Neher,
Malte C. Gather,
Donato Spoltore,
Koen Vandewal
Publication year - 2019
Publication title -
nature communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.559
H-Index - 365
ISSN - 2041-1723
DOI - 10.1038/s41467-019-11717-5
Subject(s) - optoelectronics , organic solar cell , polariton , coupling (piping) , exciton , active layer , absorption (acoustics) , materials science , band gap , acceptor , organic semiconductor , semiconductor , photon , physics , layer (electronics) , nanotechnology , optics , condensed matter physics , polymer , thin film transistor , metallurgy , composite material
Strong light-matter coupling can re-arrange the exciton energies in organic semiconductors. Here, we exploit strong coupling by embedding a fullerene-free organic solar cell (OSC) photo-active layer into an optical microcavity, leading to the formation of polariton peaks and a red-shift of the optical gap. At the same time, the open-circuit voltage of the device remains unaffected. This leads to reduced photon energy losses for the low-energy polaritons and a steepening of the absorption edge. While strong coupling reduces the optical gap, the energy of the charge-transfer state is not affected for large driving force donor-acceptor systems. Interestingly, this implies that strong coupling can be exploited in OSCs to reduce the driving force for electron transfer, without chemical or microstructural modifications of the photo-active layer. Our work demonstrates that the processes determining voltage losses in OSCs can now be tuned, and reduced to unprecedented values, simply by manipulating the device architecture.