Antireflection

Antireflection

The surface of the eyes of specific kinds of night-flying moths are covered in sub-wavelength pillars which act as an antireflective coating. By mimicking these "moth-eye" structures, high quality antireflective surfaces can be made for solar cells .

Moth-eye

Fabricated "moth-eye" structures

Most of the moth-eye structures that have been fabricated so far are expensive, and based on electron beam lithography. Nevertheless, these structures have allowed a detailed optical investigation of a large number of patterns and symetries. We are now trying to find the very best nanostructured black for all wavelengths and all angles of incidence. We are also exploring cheaper depostion techniques particulary Nanoimprint lithography , and nanosphere lithography (where tiny spheres are deposited on a surface then etched to form pillars).

These "moth-eye" surfaces, are important for many applications, the same techniques applied to transparent materials to reduce reflection, (we have been exploring the transparent wings of some species of moth). Reduced reflection from windows, will also be useful for the window used in solar cell modules, as well as displays. The technique can also be form the basis of anti-glare and stealth technologies.

Associated Reading