Optimal design of nano-scale surface light trapping structures for enhancing light absorption in thin film photovoltaics

Abstract

We present the effect of nanophotonic light trapping structures on optical absorption enhancement of crystalline silicon thin film solar cells, based on a rigorous coupled-wave analysis method. The calculation involves three different structures (i.e., hole, inverted-cone, and inverted-paraboloid), which are commonly applied on the top surface of thin film solar cells. Systematical calculation results in terms of geometrical parameters reveal sweet spots (i.e., optimum geometric structure) to obtain the highest cell efficiency for each structure, which provide a design guideline in thin film photovoltaic devices. (C) 2013 AIP Publishing LLC.