With the development of dye-sensitized solar cells (DSC), conventional solid-state photovoltaic technologies are now challenged by devices functioning at a molecular and nano-level. Record efficiencies of up to 12 per cent, promising stability data, and means of energy efficient production methods have been accomplished. The book "Molecular Solar Cells" includes solar cells employing photoelectric dye molecules to harvest sunlight and convert the photons to charge carriers which produce electricity. Since a molecular monolayer of a dye at maximum absorbs a few percent of the incident light the development of molecular solar cells have followed two main routes; the application of multi-layers (so called Tang-cells), and the use of highly structured interfaces or films of high internal surface area (DSC or Gratzel-cells). This book will deal with DSC type molecular solar cells, but will also include sections of general character such as photochemistry, driving force, electron-transfer kinetics, charge carrier separation, charge transport processes, electrical contact properties, experimental techniques for characterization, etc. This will be the first textbook of dye-sensitized molecular solar cells. There is therefore a strong need of a textbook for students and researchers in the field of molecular solar cells. The book is written for undergraduate and graduate students pursuing their M. Sc. or Ph. D. degrees in Molecular Photovoltaics or related fields dealing with photoelectrochemistry, semiconductor/electrolyte junctions, conversion of light to electricity and/or chemistry with the use of dye molecules. It is also intended to be a useful source of information and references for research groups, industries and in education dealing with emerging nanotechnologies and molecular devices for solar energy production.