Self-powered photoelectric sensors based on hydrogel diodes doped with photoacid

Artificial retina requires photo-sensory units that convert light into electric signals without relying on any external power supply. Recent development on hydrogel diodes paves a new avenue for creating photo-electric signals that can be picked up by human optic nerves. Here, we report a self-powered photoelectric sensor based on hydrogel diodes doped with photoacid, which produces electric signal relying on no external power supply. The photoelectric sensor is self-powered due to the fact that the photoacid-released protons are mobilized under the influence of the built-in electric field in the hydrogel PN junction. The photo-induced open-circuit voltage reaches to 1.6 mV under 50 mW cm−2. We found that the highest electric response occurred when photoacid was presented at the cationic side of the hydrogel PN junction. A prototype consisting 9-element sensor array is prepared, and we have demonstrated its potential for spatially resolved visualization upon light irradiation.