Field emission properties of multi-level self assembled mesoscopic structures on nanoporous templates

We report a new multi-modal self assembly technique in which a rich structural diversity of distinct moieties emerge when thin films of a wide variety of materials are deposited on nanoporous substrates using different techniques. We also report multi-level self assembly where one set of self assembled nanostructures seeds the self assembly of another set. The multi-modal self assembly has been observed using flexible alumina templates containing hexagonal arrays of cylindrical pores that are 50 nm wide and 500 nm in length and also on nanoporous Si templates. The latter were formed by anodization of thin film alumina templates deposited on platinum coated silicon substrates. The deposition parameters leading to the observation of each of the moieties will be discussed in detail and the field emission (FE) properties, measured by scanning anode field emission microscopy (SAFEM), will be reported.