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Science for an ocean nation : update of the Ocean Research Priorities Plan / Subcommittee on Ocean Science and Technology -- Executive Order 13547 : stewardship of the ocean, our coasts, and the Great Lakes / The White House Ofice of the Press Secretary

This work is part of the inter-laboratory collaboration to study the stability of seven distinct sets of state-of-the-art organic photovoltaic (OPV) devices prepared by leading research laboratories. All devices have been shipped to and degraded at RISempty set-DTU up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. In this work, we apply the Incident Photon-to-Electron Conversion Efficiency (IPCE) and the in situ IPCE techniques to determine the relation between solar cell performance and solar cell stability. Different ageing conditions were considered: accelerated full sun simulation, low level indoor fluorescent lighting and dark storage. The devices were also monitored under conditions of ambient and inert (N-2) atmospheres, which allows for the identification of the solar cell materials more susceptible to degradation by ambient air (oxygen and moisture). The different OPVs configurations permitted the study of the intrinsic stability of the devices depending on: two different ITO-replacement alternatives, two different hole extraction layers (PEDOT:PSS and MoO3), and two different P3HT-based polymers. The response of un-encapsulated devices to ambient atmosphere offered insight into the importance of moisture in solar cell performance. Our results demonstrate that the IPCE and the in situ IPCE techniques are valuable analytical methods to understand device degradation and solar cell lifetime. ; This work has been supported by the Danish Strategic Research Council (2104-07-0022), EUDP (j.no. 64009-0050), and the Danish National Research Foundation. Partial financial support was also received from the European Commission as part of the Framework 7 ICT 2009 collaborative project HIFLEX (grant no. 248678), partial financial support from the EUIndian framework of the "Largecells" project that received funding from the European Commission's Seventh Framework Programme (FP7/2007-2013. grant no. 261936), partial financial support was also received from the European Commission as part of the Framework 7 ICT 2009 collaborative project ROTROT (grant no. 288565) and from PVERA-NET (project acronym POLYSTAR). To CONACYT (Mexico) for the Ph.D. scholarship awarded to G. T.-E, to the Spanish Ministry of Science and Innovation, MICINN-FEDER project ENE2008-04373, to the Consolider NANOSELECT project CSD2007-00041, to the Xarxa de Referencia en Materials Avancats per a l'Energia, XaRMAE of the Catalonia Government (Spain). RR and HH are grateful for financial support from the Thuringian Ministry of Culture and the German Federal Ministry of Education and Research in the frameworks of FIPV II and PPP (contract number 13N9843), respectively. DMT acknowledges generous support from the Inger and Jens Bruun Foundation through The American-Scandinavian Foundation.

The present work is the fourth (and final) contribution to an inter-laboratory collaboration that was planned at the 3rd International Summit on Organic Photovoltaic Stability (ISOS-3). The collaboration involved six laboratories capable of producing seven distinct sets of OPV devices that were degraded under well-defined conditions in accordance with the ISOS-3 protocols. The degradation experiments lasted up to 1830 hours and involved more than 300 cells on more than 100 devices. The devices were analyzed and characterized at different points of their lifetimes by a large number of non-destructive and destructive techniques in order to identify specific degradation mechanisms responsible for the deterioration of the photovoltaic response. Work presented herein involves time-of-flight secondary ion mass spectrometry (TOF-SIMS) in order to study chemical degradation in-plane as well as in-depth in the organic solar cells. Various degradation mechanisms were investigated and correlated with cell performance. For example, photo-oxidation of the active material was quantitatively studied as a function of cell performance. The large variety of cell architectures used (some with and some without encapsulation) enabled valuable comparisons and important conclusions to be drawn on degradation behaviour. This comprehensive investigation of OPV stability has significantly advanced the understanding of degradation behaviour in OPV devices, which is an important step towards large scale application of organic solar cells. ; This work has been supported by the Danish Strategic Research Council (2104-07-0022), EUDP (j.no. 64009-0050, 64009-0051) and the Danish National Research Foundation. Partial financial support was also received from the European Commission as part of the Framework 7 ICT 2009 collaborative project HIFLEX (grant no. 248678), partial financial support from the EUIndian framework of the "Largecells'' project that received funding from the European Commission's Seventh Framework Programme (FP7/2007-2013. grant no. 261936), partial financial support was also received from the European Commission as part of the Framework 7 ICT 2009 collaborative project ROTROT (grant no. 288565) and from PVERA-NET (project acronym POLYSTAR). are due to CONACYT (Mexico) for the PhD scholarship awarded to G. T.-E; to the Spanish Ministry of Science and Innovation, MICINN-FEDER project ENE2008-04373; to the Consolider NANOSELECT project CSD2007-00041; to the Xarxa de Referencia en Materials Avancats per a l'Energia, XaRMAE of the Catalonia Government (Spain). RR and HH are grateful for financial support from the Thuringian Ministry of Culture and the German Federal Ministry of Education and Research in the frameworks of FIPV II and PPP (contract number 13N9843), respectively. DMT acknowledges generous support from the Inger and Jens Bruun Foundation through The American-Scandinavian Foundation.