Process and design guidelines for inkjet-printed organic photovoltaic cells - using the example of PM6:Y6

Inkjet printing (IJP) is a promising non-contact and digital technique for the precise deposition and patterning of functional materials on reduced areas, enabling versatile applications in both indoor and outdoor environments. In this work, we present processing and design guidelines for IJP the active layer of organic photovoltaics (OPVs), covering ink preparation with non-halogenated solvents, film printing, and post-treatment. The benchmark PM6:Y6 system, a well-known high-performance donor-acceptor combination that remains relatively unexplored in the IJP field, and a commercially available IJP system are selected as a case study. Trends in power conversion efficiency (PCE) were observed with respect to the studied parameters, providing insight into the morphology-performance relationship of IJP films. Maximum optimized PCEs of 3.31% under 1 sun and 4.37% under 500 lux indoor illumination were achieved for IJP active layers produced at ambient conditions. This study highlights not only the feasibility of eco-friendly, inkjet-printed OPVs, but also general process trends to guide the fabrication of efficient, miniaturized devices for the Internet of Things (IoT), wearable electronics, and other low-power electronics applications.