The sun is an ultimate source of clean energy which is available in abundance. One hour of solar energy retrieved from sunlight is equivalent to the world's total energy consumption in a complete year (i.e., 16 TW). The development of low cost and highly efficient photovoltaic technology is a vital scientific goal and researchers have been trying to achieve it in the past two decades. The novel synthesis technique for preparation of solar cells has attracted significant interest because of their smart features which include low-temperature synthesis, synthetic variability, and the probability of fabricating flexible, lightweight, and green photovoltaic cells. Nanotechnology is the technology of future. It has a wide ranging domain of applications in almost every field of human activity which include chemical engineering, materials science, medicine, electronics, energy sector, etc. Presently, the use of nanotechnology in manufacturing of solar cells is gaining a significant attention due to its ability to provide cost-efficient and eco-friendly green energy solutions. Each chapter of this book recapitulates the applications of nanotechnology for development of green energy solutions. Introductory chapters of the book also contain the applications of nanotechnology beyond photovoltaics, and the key fabrication techniques, followed illustration of particular nanostructure type produced by application of a certain synthesis technique. The book also examines the benefits of each nanotechnology technique with a stress on probable future avenues of research.