Nanohole

Nanoholes are a class of nanostructured material consisting of nanoscale voids in a surface of a material.

Not to be confused with nanofoam or nanoporous materials which support a network of voids permeating throughout the material (often in a disordered state), nanohole materials feature a regular hole pattern extending through a single surface.

These can be thought of as the inverse of a nanopillar or nanowire structure.

Nanohole structures have been used for a variety of applications, ranging from superlenses produced from a metal nanohole array,[1] to structured photovoltaic devices used to improve carrier extraction,[2] and light absorption.

[3] Nanohole structures are also extensively utilized for the creation of photonic crystals, particularly for creating photonic crystal waveguides.

Angled cross-sectional scanning electron micrograph of a nanohole array etched in amorphous silicon, with a thin conductive polymer coating. Scale bar is 200 nm.