Retinomorphic Motion Detector and Supercapacitors Based on Organic Semiconductors

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 structure, 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 resistor-capacitor 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/>In addition to discussing the development of organic optical sensors, this presentation will also show the use of the same class of organic semiconductors in energy storage applications, in particular for redox supercapacitors as portable power sources. We developed multifunctional structures, which combine load-bearing and energy-storage functions in one, resulting in weight savings and safety improvements. We demonstrated a gradient electrolyte design to facilitate high ionic conductivity at the electrode-electrolyte interfaces and transitioned to a composition with high mechanical strength in the bulk for load support. The gradient design enabled the multilayer structural supercapacitors to reach state-of-the-art performance matching the level of mono-functional supercapacitors. Finally, the structural supercapacitor was made into the hull of a model boat to demonstrate its multifunctionality.