Simulation analysis of GaN microdomes with broadband omnidirectional antireflection for concentrator photovoltaics

Abstract

Microdome structures are analyzed as surface topology to reduce surface reflection over a broad spectral range and wide light incidence angle for concentrator photovoltaics application. Three dimensional finite difference time domain method was used to accurately calculate the surface reflection and transmission for surface topologies with different feature sizes and aspect ratios. Studies show that the use of GaN microdomes will lead to a significant reduction of the surface reflection over a broad wavelength range and wide incidence angle range. The surface reflection significantly depends on the surface structure feature size and geometrical shape. The design of the GaN microdomes provides flexibility to tune the structure in order to obtain the minimum surface reflection for different designs of concentrator optical systems. The surface reflections of the GaN microdomes are compared with that of the conventional flat surface as well as the one with antireflection coating.