Retinomorphic Motion Sensors and Integrated Energy Storage Systems Based on Donor-Acceptor Polymers

Organic retinomorphic sensors offer the advantage of in-sensor processing to filter out redundant static background and are well suited for motion detection. To improve this promising photodetector, here we studied the key role of interfacial energetics in promoting charge accumulation to raise the inherent photoresponse of the light-sensitive capacitor. Specifically, incorporating appropriate interfacial layers around the photoactive layer was crucial to extend the carrier lifetime, as confirmed by intensity-modulated photovoltage spectroscopy. Compared to its photodiode counterpart, the retinomorphic sensor showed better detectivity and response speed due to the additional insulating layer, which reduced the dark current and the RC time constant. Lastly, three retinomorphic sensors were integrated into a line array to demonstrate the detection of movement speed and direction, showing the potential of retinomorphic designs for efficient motion tracking.<br/> <br/>In addition to enabling motion detector, the class of donor-acceptor polymers showed highly delocalized redox states and operated as stable n-type anodes in energy storage devices. The redox polymer was used in supercapacitors and achieved a high areal power density of 227 mW/cm², allowing rapid charging and high power delivery. The capacitance retention was 84% after 11,000 full redox cycles, offering the critical benefit of long cycle life. This work demonstrated the application of a new class of stable redox-active materials suitable to meet the energy storage needs for short-range wireless electronics.