Current transport mechanism at metal-semiconductor nanoscale interfaces based on ultrahigh density arrays of p-type NiO nano-pillarsElectronic supplementary information (ESI) available. See DOI: 10.1039/c3nr03803c

• Main Authors: Nandy, Suman, Gonçalves, Gonçalo, Pinto, Joana Vaz, Busani, Tito, Figueiredo, Vitor, Pereira, Luís, Paiva Martins, Rodrigo Ferrão, Fortunato, Elvira
• Format: Journal Article
• Language: English
• Published: 07.11.2013
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c3nr03803c

The present work focuses on a qualitative analysis of localised I - V characteristics based on the nanostructure morphology of highly dense arrays of p-type NiO nano-pillars (NiO-NPs). Vertically aligned NiO-NPs have been grown on different substrates by using a glancing angle deposition (GLAD) technique. The preferred orientation of as grown NiO-NPs was controlled by the deposition pressure. The NiO-NPs displayed a polar surface with a microscopic dipole moment along the (111) plane (Tasker's type III). Consequently, the crystal plane dependent surface electron accumulation layer and the lattice disorder at the grain boundary interface showed a non-uniform current distribution throughout the sample surface, demonstrated by a conducting AFM technique (c-AFM). The variation in I - V for different points in a single current distribution grain (CD-grain) has been attributed to the variation of Schottky barrier height (SBH) at the metal-semiconductor (M-S) interface. Furthermore, we observed that the strain produced during the NiO-NPs growth can modulate the SBH. Inbound strain acts as an external field to influence the local electric field at the M-S interface causing a variation in SBH with the NPs orientation. This paper shows that vertical arrays of NiO-NPs are potential candidates for nanoscale devices because they have a great impact on the local current transport mechanism due to its nanostructure morphology. The present work focuses on a qualitative analysis of localised I - V characteristics based on the nanostructure morphology of highly dense arrays of p-type NiO nano-pillars (NiO-NPs).