Reliable, Neutral-color, Semi-transparent Organic Photovoltaics for Power Generating Windows Applications*

Semi-transparent organic photovoltaics (ST-OPVs) can be integrated with windows of buildings and vehicles for the purpose of clean power generation. To fulfill this application, ST-OPVs must be reliable, efficient, and often neutral in color. Recent studies have revealed that, while fullerene-based OPVs are highly reliable¹, they are opaque and thus unsuitable for window applications. The replacement of fullerenes with of non-fullerene acceptors (NFAs) have led to increased power conversion efficiencies, but have considerably shorter lifetimes when used in devices. Recent innovations in the design of NFA-based opaque OPVs have achieved extrapolated lifetimes of at least 30 years². A remaining challenge is the demonstration of long-lived, NFA-based, neutral-color ST-OPVs³. In this work, we optically design an NFA-based ST-OPV for neutral-color, high efficiency, and long operational stability. We demonstrate that these devices maintain > 95 % of their initial electrical and optical properties after 1500 h of exposure to 1 sun intensity, AM 1.5G illumination.