Building a depletion-region width modulation model and realizing memory characteristics in PN heterostructure devices

-Si/n-ZnO and p-NiO/n-ZnO heterostructure devices. A high external electric field induces the migration of oxygen ions and electrons/holes between the p-type and n-type semiconductor layers. It can regulate the oxygen vacancy concentration of the n-type side and cation vacancy concentration of the p-type side, changing the depletion-region width and modulating device conductivity and capacitance. Several essential synaptic functions were accurately imitated, including spike-timing-dependent plasticity (STDP) and "learning-experience" behaviors. This work provides new opportunities in fabricating a memristor and memcapacitor based on a PN heterostructure for synaptic simulation.