Mem-capacitance enabled volatile switching in Dopamine@Agarose-based devices

The development of biocompatible, environmentally friendly, and low-cost functional switching materials for memory and synaptic learning devices has gained importance in recent years. Dopamine is a naturally occurring biomaterial that has been used in various fields. In the present study, dopamine@agarose was used as a switching layer, sandwiched between Ag top and FTO bottom electrodes to form the Ag/dopamine@agarose/FTO device. The agarose was utilized due to its natural polymeric properties and its functionality as a binder. The switching layer was characterized using UV–vis spectroscopy, Fourier transform infrared spectroscopy, atomic force microscopy, and field emission scanning electron microscopy. The non-pinched hysteresis curve revealed the mem-capacitive behaviour of the device, which was corroborated using electrochemical and frequency-dependent capacitance-voltage studies. The charge-flux properties depicted the non-ideal memristor nature of the device. Furthermore, the cumulative probability and Weibull distribution were studied to understand the switching variability. The fabricated device demonstrates a stable multilevel volatile memory effect over 15000 cycles. The results assert that dopamine can be a potential candidate for developing sustainable volatile memory devices.