Nanoscale interface formation and charge transfer in graphene/silicon Schottky junctions; KPFM and CAFM studies

In this study, nanoscale interface formation and photogenerated carrier transfer in Schottky-junction between CVD graphene and n-Si wafer have been investigated using CAFM and KPFM techniques. The difference in the surface potential images of graphene observed on applying voltage between tipgraphene and tip-Si under light conditions has been understood in terms of holes transfer to graphene resulting in the shift of Fermi level and the open circuit voltage variations at the junction. A decrease in surface potential due to PMMA residues and an increase in surface potential near wrapping boundaries are the main reasons for the variation in photovoltaic parameters. (C) 2015 Elsevier Ltd. All rights reserved.