Carrier transport mechanism of diamond p+–n junction at low temperature using Schottky–pn junction structure

Abstract

We elucidate the carrier transport mechanism from the p+-layer (metallic-conduction) to the n-layer (band-conduction) in a diamond p+–n junction, which is the basic structure of diamond devices. We fabricate Schottky–pn diodes containing p+–n junctions and analyze the temperature dependence of electrical properties in the forward bias region. At temperatures higher than the cryogenic region, free holes transport from the p+-layer to the n-layer. In the cryogenic region, which is insufficient to excite holes to the valence band, the direct transport of holes from the effective carrier conduction level in the p+-layer to the n-layer by tunneling becomes dominant.