Watching Space Charge Build Up in an Organic Solar Cell

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Sebastian Wilken, Oskar J. Sandberg, Dorothea Scheunemann, Ronald Österbacka
Publisher: WILEY-VCH Verlag GmbH & Co. KGaA
Place: Weinheim
Publication year: 2020
Journal: Solar Rrl
Journal acronym: solar-rrl
Volume number: 2020
Issue number: 4
Start page: 1
End page: 8
eISSN: 2367-198X


Space charge effects can significantly degrade charge collection in organic
photovoltaics (OPVs), especially in thick-film devices. The two main causes
of space charge are doping and imbalanced transport. Although these are
completely different phenomena, they lead to the same voltage dependence
of the photocurrent, making them difficult to distinguish. Herein, a method is
introduced on how the build-up of space charge due to imbalanced transport can
be monitored in a real operating organic solar cell. The method is based on the
reconstruction of quantum efficiency spectra and requires only optical input
parameters that are straightforward to measure. This makes it suitable for the
screening of new OPV materials. Furthermore, numerical and analytical means
are derived to predict the impact of imbalanced transport on charge collection. It
is shown that when charge recombination is sufficiently reduced, balanced
transport is not a necessary condition for efficient thick-film OPVs.

Last updated on 2020-26-05 at 06:09