Charge Transport in Porous Silicon/Graphene-Based Nanostructures

Abstract

In this study hybrid structures were created by deposition of the graphene oxide and the reduced graphene oxide on the porous silicon layer. The charge transport and relaxation processes in obtained structures were analyzed on the basis of comprehensive studies of conductivity and depolarization current in the 90–325 K temperature range within the model of disordered semiconductors. Hopping conductivity and activation mechanism of charge transport in different temperature ranges were established and the activation energy of the conductivity was determined. Localized electron states that affect the charge transport in the porous silicon/graphene-based structures were found by means of thermally stimulated depolarization spectroscopy. It has been revealed that the adsorption of water molecules changes resistive and capacitive parameters of hybrid structures. Found features of the charge transport processes expand the prospects of application of such nanomaterials for sensor electronics.

Keywords:

• porous silicon
• graphene
• graphene oxide
• conductivity
• thermally stimulated depolarization
• humidity sensor