Laminated Organic Photovoltaic Modules for Agrivoltaics and Beyond: An Outdoor Stability Study of All‐Polymer and Polymer:Small Molecule Blends

• Published in: Advanced functional materials Vol. 33; no. 10
• Main Authors: Rodríguez‐Martínez, Xabier, Riera‐Galindo, Sergi, Aguirre, Luis Ever, Campoy‐Quiles, Mariano, Arwin, Hans, Inganäs, Olle
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01.03.2023
• Subjects: agrivoltaics; building integrations; Chloroplasts; Crop growth; Greenhouses; Harvesters; laminated solar cells; Laminates; Materials science; organic photovoltaics; outdoor stability; Photovoltaic cells; Polymer blends; Polymers; Tandem configuration; Thermal stability; outdoor stability; building integrations; agrivoltaics; laminated solar cells; organic photovoltaics
• ISSN: 1616-301X; 1616-3028; 1616-3028
• DOI: 10.1002/adfm.202213220

The integration of organic photovoltaic (OPV) modules on greenhouses is an encouraging practice to offset the energy demands of crop growth and provide extra functionality to dedicated farmland. Nevertheless, such OPV devices must meet certain optical and stability requirements to turn net zero energy greenhouse systems a reality. Here a donor:acceptor polymer blend is optimized for its use in laminated devices while matching the optical needs of crops. Optical modeling is performed and a greenhouse figure‐of‐merit is introduced to benchmark the trade‐off between photovoltaic performance and transparency for both chloroplasts and humans. Balanced donor:acceptor ratios result in better‐performing and more thermally stable devices than acceptor‐enriched counterparts. The optimized polymer blend and state‐of‐the‐art polymer:small‐molecule blends are next transferred to 25 cm2 laminated modules processed entirely from solution and in ambient conditions. The modules are mounted on a greenhouse as standalone or 4‐terminal tandem configurations and their outdoor stability is tracked for months. The study reveals degradation modes undetectable under laboratory conditions such as module delamination, which accounts for 10–20% loss in active area. Among the active layers tested, polymer:fullerene blends are the most stable and position as robust light harvesters in future building‐integrated OPV systems. Laminated organic photovoltaic devices based on polymer blends are designed to match the optical needs of crop growth. 25 cm2 modules are deployed on a domestic greenhouse and their outdoor stability is tracked for months. Further degradation modes are identified, e.g., delamination, which drops the active area by 10–20%.