The dye-sensitized solar cells (DSSCs) are still in the early stages. This book would be helpful to educate the people towards alternative energy sources. Additionally, these energy sources would be pollution free as compared to coal which is a source of electricity. Until now, it's a severe challenge for both experiment and theory to make clear the fundamental properties of the ultrafast electron injection and come up to the satisfied efficiency of DSSC. Further developments in dye design will play a vital part in the continuing optimization of DSSC and it depends on the quantitative knowledge of dye sensitizer. So the theoretical investigations of the physical properties of dye sensitizers are very important in order to disclose the relationship among the performance, structures and the properties, it is also supportive to design and production of novel dye sensitizers with higher performance. Porpyrins are the stable organic chromophores which absorb visible light well and, luminesce with very high efficiency. The present book deals with the Structural, electronic and photophysical properties as well as structure-property relationship.