Effect of CdO interlayer on electrical characteristics in Sesingle bondBi diodes

The introduction of an interlayer of CdO, of thickness up to 0.42 μm, between a layer of crystallized selenium and one of bismuth in the form of a Sesingle bondCdOsingle bondBi diode, was found to increase the frequency below which negative capacitance appeared in forward bias. The effect is attributed either to increased carrier transit time across the interlayer or to a reduction of internal capacitance in the presence of an existing inductive influence. An equivalent circuit model of a Se-metal diode, involving a hypothetical fixed inductor, was developed, which correctly traces out the type of observed variation of measured diode capacitance with bias and frequency.