Energy conversion efficiency is a critical consideration in the application of silicon solar cells. Texturing of both the front side and the backside of silicon solar cells has been used in the past to increase the absorption of infrared sun light energy in silicon solar cells. A review is given of some of the basic concepts and then a design described for the optimal textured structure that can result in improvements in conversion efficiency of up to 20% on crystalline silicon solar cells and up to 40% on thin film silicon solar cells. Some of the practical limitations are described in realizing these structures in silicon technology. (C) 2011 Elsevier Ltd. All rights reserved.