This book converses the various aspects of materials for the fabrication of counter electrodes, especially for dye-sensitized solar cells (DSSCs) which arebelieved to be the most promising in the third-generation solar photovoltaics (PVs). The optimization of a DSSC is focused on four main components: (i) metal oxide semiconductor, (ii) photosensitizer, (iii) redox couple electrolyte, and (iv) counter electrode. Among these, the counter electrode undertakes three functions: (i) as a catalyst, (ii) as a positive electrode of primary cells, and (iii) as a mirror. To obey these functions, the electrode material should have high catalytic activity, high conductivity, high reflectivity, high surface area, and electrochemical and mechanical stability. To improve the performance of DSSCs, many scientists have developed new counter electrodes made of platinum, carbon materials, transition metals, conductive polymers, and composites. Renewable energies have become an attractive option to overcome the energy demands in sustainable and affordable ways. Of the various renewable energies, one-third of the energy generation would be from PVs.