Electrical properties of heavily doped μc-Si:H

Abstract

We have investigated the conduction in heavily doped μc-Si:H samples grown by glow discharge by measuring the conductivity and the Hall coefficient in a wide temperature range. We show that the conductivity of these materials cannot be satisfactorily interpreted using the models already present in the literature. We put forward a model in which the material is considered composed of small crystalline grains embedded in an amorphous tissue and in which potential barriers exist between adjacent grains due to the band discontinuities. A comparison between detailed calculations and transport data shows that the tunneling (probably aided by the presence of localized states) is the fundamental conduction mechanism.