Current-voltage characteristics of metal-oxide-oxide-metal structures with several regions of negative differential resistance

We have studied the current-voltage (I-U) characteristics of heterostructures of the metal-oxide-oxide-metal type formed in a pressure contact of aluminum and zinc electrodes covered by natural oxide layers. It is established that the I-U curves of such structures can exhibit several N-shaped regions of negative differential resistance at both positive and negative bias voltages. This phenomenon can be of interest in designing oscillators, amplifiers, and frequency converters for high-frequency range and should be taken into account in selecting their operation regimes.