Carrier transport of diamond p + ‐i‐n + junction diode fabricated using low‐resistance hopping p + and n + layers

We have investigated the carrier transport of a single‐crystal diamond p + ‐i‐n + junction diode fabricated using low‐resistance hopping p + and n + layers, which showed high‐performance diode characteristics. By comparing the diode characteristics of the p + ‐i‐n + junction with those of the p + ‐n + diode and metal/n + /metal structure, the following results were obtained. The carrier transport of the p + ‐i‐n + junction is described using the band conduction caused by the free carriers, although the current transport in both p + and n + layers is mainly by the hopping conduction. The i‐layer in the p + ‐i‐n + junction provides a low‐resistance layer for the forward current and a good blocking layer for the reverse current. The contact resistance of the n + /metal layer affects the carrier transport of the p + ‐i‐n + diode, which lacks the ohmic property even with the phosphorous concentration around 10 20  cm −3 .