Computational Modeling of Silicon Nanostructures for Photovoltaic Applications

Abstract

Gains in photovoltaic cell efficiency have the potential to allow solar power to increasingly become a prominent source of electrical power. One source of gain is from surface texturing and nanostructures such as nanowires, which increase optical absorption. Computational modeling is an excellent tool for design and characterization of optical devices. It allows for the investigation of a wide range of dielectric structures of multiple shapes and sizes, which saves significant time and money over building and testing each of a range of devices. It also allows engineers to design fanciful new types of structures and test them to see which are worth fabrication and further investigation; to be imaginative without being limited by the time and budget constraints of production. Branched nanowires deliver improved absorption over both planar silicon photovoltaic cells and silicon nanowires, which may increase device efficiency because of the additional photons captured. Parameter studies were performed on standard BNW and novel designs to determine an optimized geometry for broadband optical absorption. Some branched nanowires exhibit photonic crystalline behavior. This may create a complete 3-dimensional band gap.