Photovoltaic solar energy conversion is one of the most attractive non-conventional energy sources of proven reliability from the micro to the Maga watt level. This worldwide interest is attributed to a variety of factors such as search for new energy sources due to heavy pressure on conventional fuels, simplicity, cleanliness, and direct conversion into electricity. Carbon nanotubes and telluride materials have very high thermal conductivity, almost a factor of 2 more than that of diamond and telluride. Materials and its properties are the main criteria to build its applications; some of the photovoltaic materials could be used in pure form to fabricate photovoltaic applications of the materials LCD, LED, photodiodes and photo transistors. When it will be doped with oxide semiconducting materials its applications will be enhanced commercially. This book gave the simple basic ideas of its development from 19 century to recent. The technologies of the photovoltaic applications and its electronic devices were discussed.