Manifestation of disorder effects in the excess tunnel current of heavily doped silicon diodes

The temperature dependence of the forward current in heavily doped silicon p-n diodes has been measured at low temperatures, at which conduction occurs via tunneling. In the lowest temperature region, variable range hopping conduction was observed, whereas at higher temperatures the diode current exhibited a superexponential temperature dependence, which can be explained by thermotunneling through some random potential barriers.