Near‐Infrared Organic Photovoltaic Electrodes for Subretinal Neurostimulation

Abstract

Organic semiconductors are emerging as a promising class of photovoltaic materials for neural interfaces, offering high power conversion, mechanical flexibility, biocompatibility, and tunable optoelectronic properties. In this study, the application of a D18:Y6-based organic photovoltaic (OPV) electrode is investigated for subretinal stimulation in a model of retinal degeneration. It is demonstrated that OPV devices can be engineered to electrically stimulate the retina via network-mediated pathways, in a manner comparable to established neurostimulation approaches. The presented OPV electrodes reliably activate retinal ganglion cells, eliciting consistent spike responses to light pulses within the near-infrared range. The stimulation onset, spike latency, and response profiles suggest effective faradaic charge injection as a key mechanism for neuronal activation, particularly for longer pulse durations. Moreover, it is shown that both light intensity and pulse duration can be used to finely tune the neural response, offering a high degree of control over retinal ganglion cell activation. Finally, it is proven that D18:Y6 blend is biocompatible in vitro when in direct contact with human induced pluripotent stem cell (iPSC)-derived retinal organoids and mouse explants. These results validate the photo-electrical performance and biocompatibility of D18:Y6 OPVs and position them as a viable candidate for next-generation, minimally invasive retinal prosthetics.