Transport properties of Si based nanocrystalline films investigated by c-AFM

Abstract

SiOxNy is an innovative material that has recently attracted a lot of attention in different and new applications, ranging from photovoltaics, conductive oxide, carbon capture; nevertheless, due to its complex and multiphase nature, the understanding of its electrical properties is still ongoing. In this framework, the present manuscript presents the investigation of electrical transport properties of nanocrystalline (nc-) SiOxNy. In fact, non-stoichiometric nc-SiOxNy films deposited by Plasma Enhanced Chemical Vapor Deposition have been studied by conductive Atomic Force Microscopy (AFM). The analyses of samples subjected to different thermal treatments conditions and the comparison with nc-Si:H films have allowed us to clarify the role of crystallization and O content on the local conductivity of the layers. We show that the annealing treatment promotes an enhancement of conductance, a redistribution of the conductive grains in the layers and the activation of B doping. Current-voltage characteristics locally performed using the conductive AFM-tip as a nanoprobe have been modelled with thermionic emission transport mechanism.