Photoenergy is the process and science of converting light into energy, particularly into electrical energy by using materials that are semiconductors and use the photovoltaic effect. One of the most successful and widely used form of photovoltaics is solar energy derived by planting solar panels in direct sunlight and harnessing the sunlight into electricity. This book presents researches and studies performed by experts across the globe on the various aspects of photoenergy. Most of the topics introduced in this book cover new techniques and the applications of the subject. It is appropriate for students seeking detailed information in this area as well as for experts.