Organic Photovoltaics (OPV) has recently reached Power Conversion Efficiency (PCE) above the 20% milestone for outdoor applications (1 Sun, AM1.5G), and at the same time, huge efforts have been made on pushing the performance for low light indoor applications, currently reaching above 30% PCE (for small cells at research scale) under such operating conditions. These devices have huge potential for powering up Internet-of-Things (IoT) devices down to 50 lux lighting conditions, and therefore, development of high-performance indoor OPV modules that can be manufactured and scaled at industrial compatible conditions is currently in focus. In this presentation, recent work on scalable OPV cells and modules will be presented, having a focus on Roll-to-Roll (R2R) techniques for development of scalable modules at ambient air conditions for outdoor [1], and in particular new indoor applications. Firstly, a summary of the processing techniques utilized in our work for scalable OPV device development is outlined and demonstrated, spanning from R2R-based vacuum sputtering to scalable slot-die coating, to cover the full range of functional layers embedded in these OPV device stacks.

Secondly, a particular focus will be paid to development of scalable OPV modules for indoor applications at low light conditions. As indoor light sources exhibit narrower emission spectra and lower light intensities, OPV donor and acceptor materials with wider HOMO-LUMO gap are utilized, and optimized towards improved visible light absorption, high shunt resistance and stable operation under indoor light conditions. In this work, we designed and developed OPV cells and modules using PTQ10 as the polymer donor and FCC-Cl as wide-bandgap non-fullerene acceptor, employed in various different device stacks, also using new PDIN-based molecules for the electron transport layer to reach high performance [2]. Optimized small-area cells achieved a power conversion efficiency (PCE) of above 26% under 1000 lux illumination, and high stability under continuous indoor illumination. Furthermore, the developed device architecture was successfully scaled up using sheet-to-sheet (S2S) slot-die coating at ambient air conditions, utilizing green solvents for the active layer processing. PTQ10:FCC-Cl OPV modules with an active area of 13.8 cm² fabricated under such conditions reached a high PCE of 20%, under the same indoor low light conditions. The results demonstrate the strong potential of this material system and processing approach for scalable, high-efficiency indoor OPV applications.