Photovoltaic devices transform the visible part of the sunlight directly into electricity. It is a semiconductor based solar technology with the potential to supply essentially all the energy we need and is perhaps the most clean of all schemes for the exploitation of solar energy. These photovoltaic devices known as solar cells are based on the properties of certain crystalline solids that enable these materials to supply an electric current capable of performing useful work when the material is exposed to sunlight. Since the invention of solar cells for practical purposes in 1955, they have been used primarily for providing electrical power to spacecrafts, though the real value of photovoltaic lies in its potential to produce electricity at a cost cheap enough to compete with conventional sources of electricity like coal, oil, natural gas and nuclear. In view of the recent developments made in the twin fields of photovoltaics and solar cells, the present volume representing an excellent collection of topics was framed out. The topics covered in this volume include: o Characterization of the electrical performance of photovoltaic cells and modules o Conversion efficiency of large-scale photovoltaics using 3-D topographic maps o Thermo-photovoltaic generator development o Techno-economic and environmental multi-objective design of photovoltaic systems o Stand alone photovoltaic system o Grid connected solar power systems o PV electricity costs and economics of PV systems o Earth abundant alternate absorbers for future chalcopyrite photovoltaics o Solar photocatalysis to convert directly solar energy into chemical energy o Solar cells o Organic solar cells o Overview of polymer solar cells o Present status and challenges in sprayed Cu2Zn Sn S4 thin film solar cells o Cd Te absorber layer in Cd S/Cd Te thin film solar cells o Engineered nanomaterials and heterostructures for solar cell applications o Plasmonic effects of metallic nano particles in organic solar cells o Solar cell control o Effect of shadowing location and area on the dye-sensitized solar cell performance The volume 6 contains 17 articles from 40 researchers and/or academicians representing 14 nations, namely Australia, China, India, Iran, Iraq, Italy, Japan, Jordan, Mexico, Pakistan, Poland, South Korea, Spain, Switzerland and United Kingdom giving an overview of the various research activities being carried out in different parts of the world in the fields of Photovoltaics and Solar Cells.