Publication date: 11th March 2026
Despite power conversion efficiencies (PCEs) surpassing 20%, [1,2] organic solar cells still suffer from limited lifetimes due to intrinsic stability issues of the molecules that constitute the photoactive layer.[3,4] In this study, we focus on thin films of the state-of-the-art donor polymer PM6, the small molecule non-fullerene acceptor (NFA) Y6, and their blend, and investigate their light-induced degradation under AM 1.5 illumination in air. We investigated the influence of processing solvent and the effect of spectral filtering of the light on the degradation process. When PM6:Y6 blend films are exposed to unfiltered light or 400 nm long-pass filtered light conditions, the blend can degrade via several pathways, including direct photodegradation, superoxide formation through electron transfer, and singlet oxygen formation via energy transfer to ambient oxygen. We found that, when PM6:Y6 blend films were exposed to 665 nm long-pass filtered light, the dominant pathway for degradation was singlet oxygen formation via energy transfer from the acceptor to ambient oxygen and subsequent photooxidation of both donor and acceptor.[4] Further, we found that PM6:Y6 films prepared from two different solvents, chloroform and chlorobenzene, showed significantly different photodegradation rates. The cause of this difference was found to be related to morphological differences, as chloroform-processed films are smoother and contain preferentially face-on oriented acceptor molecules, as deduced from the angular dependence of the Near Edge X-Ray Absorption Fine Structure spectra at the nitrogen K-edge. These differences are also translated into device performance, with PM6:Y6 solar cells processed from chloroform being significantly more efficient than those processed from chlorobenzene solutions. Finally, these devices were degraded under AM 1.5 light for up to 100 minutes in ambient conditions. Despite their differences mentioned above, the photodegradation rate was found to be independent of the processing solvent.
The authors would like to thank Dr Hanmin Zhang, Dr Leif K. E. Ericsson, and Shahna Mysin Kadakkotteeri at Karlstad University, Sweden, for their assistance with the NEXAFS experiments. The author would like to acknowledge the synchrotron facility at FlexPES beamline, MAX IV Laboratory, Sweden, under Proposal 20241616, and PIRX beamline, SOLARIS, Poland, under Proposal 20227087. Research conducted at MAX IV, a Swedish national user facility, is supported by the Swedish Research Council under contract 2018-07152 and the Swedish Governmental Agency for Innovation Systems under contract 2018-04969. Research at the National Synchrotron Radiation Centre SOLARIS is supported by the Ministry of Science and Higher Education, Poland, under contract no. 1/SOL/2021/2. This work was partially supported by the Wallenberg Initiative Materials Science for Sustainability (WISE) funded by The Knut and Alice Wallenberg Foundation (Grant Nr. WISE-AP01-PD08). EM acknowledges the Swedish Energy Agency (contract 48598-1) for financial support of the project. The Knut and Alice Wallenberg Foundation (grant number 2016.0059) is acknowledged for financial support for the research equipment used in the project. We also acknowledge funding through the PRISMAS program from the European Union’s COFUND action, within the European Commission MSCA framework (grant agreement ID: 101081419).
nanoGe is a prestigious brand of successful science conferences that are developed along the year in different areas of the world since 2009. Our worldwide conferences cover cutting-edge materials topics like perovskite solar cells, photovoltaics, optoelectronics, solar fuel conversion, surface science, catalysis and two-dimensional materials, among many others.
Previously nanoGe Spring Meeting (NSM) and nanoGe Fall Meeting (NFM), MATSUS is a multiple symposia conference focused on a broad set of topics of advanced materials preparation, their fundamental properties, and their applications, in fields such as renewable energy, photovoltaics, lighting, semiconductor quantum dots, 2-D materials synthesis, charge carriers dynamics, microscopy and spectroscopy semiconductors fundamentals, etc.
International Conference on Hybrid and Organic Photovoltaics
International Conference on Hybrid and Organic Photovoltaics (HOPV) is celebrated yearly in May. The main topics are the development, function and modeling of materials and devices for hybrid and organic solar cells. The field is now dominated by perovskite solar cells but also other hybrid technologies, as organic solar cells, quantum dot solar cells, and dye-sensitized solar cells and their integration into devices for photoelectrochemical solar fuel production.
Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics
The main topics of the Asia-Pacific International Conference on Perovskite, Organic Photovoltaics and Optoelectronics (IPEROP) are discussed every year in Asia-Pacific for gathering the recent advances in the fields of material preparation, modeling and fabrication of perovskite and hybrid and organic materials. Photovoltaic devices are analyzed from fundamental physics and materials properties to a broad set of applications. The conference also covers the developments of perovskite optoelectronics, including light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.
The International Conference on Perovskite Thin Film Photovoltaics Perovskite Photonics and Optoelectronics (NIPHO) is the best place to hear the latest developments in perovskite solar cells as well as on recent advances in the fields of perovskite light-emitting diodes, lasers, optical devices, nanophotonics, nonlinear optical properties, colloidal nanostructures, photophysics and light-matter coupling.