Studies on nanostructured anti-reflective coatings

Abstract

Minimizing reflection losses in glass substrates can increase the proportion of light transmitting to optoelectronic devices and thus, can potentially enhance their performance. Anti-reflective coatings (ARC) on glass substrates for this purpose present challenges with regard to their fabrication, broadband and omnidirectional performance and durability. In this thesis porous nanostructured ARC and moth?s eye nanostructure patterns on glass substrates have been analysed based on their anti-reflection characteristics over broader spectrum and increasingly oblique angles of incidence. These two types of ARC are also studied for their durability as well as repellence to water droplets and humidity. Based on the observation that the moth?s eye anti-reflective nanostructure patterns offer broadband and omnidirectional anti-reflection as well as better durability and water repellence, the patterns have been replicated on top of micro-lens arrays. These hierarchical arrays called the multi-scale ommatidial arrays exhibit far superior anti-reflection and water repellence properties.