The glancing angle deposition (GLAD) technique, unlike a conventional physical vapor deposition (PVD) process,
incorporates a flux of atoms that are obliquely incident on a tilted and rotating substrate. Instead of a continuous thin
film coating, these atoms can form arrays of three-dimensional nanostructures due to a shadowing effect. By simply
controlling the deposition angle and substrate rotation speed, nanostructures of a large variety of materials in the shapes
of rods, screws, or springs can be obtained easily that are otherwise difficult to produce by conventional lithographical
techniques. In this study, a brief overview of the growth mechanisms of GLAD nanostructures is presented. In addition,
a new small angle deposition (SAD) technique as a simple means of conformally coating nanorod or nanowire arrays is
described. SAD utilizes a small tilt angle during PVD on nanostructured substrates, which allows the effective exposure
of nanorod sidewalls to the incoming flux and leads to enhanced thin film conformality. In this work, some recent results
on core-shell nanorod arrays obtained by coating GLAD nanorods with a SAD shell will be presented. It will be shown
that core-shell nanostructured geometries obtained by the simple SAD-GLAD method can significantly enhance catalyst
activity for fuel cell electrodes, and charge carrier collection efficiency in photoconductive/semiconductor
nanostructured materials.
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