Solar energy can be harvested either by deriving directly from sunlight or by indirect methods. A variety of technologies have been developed to harness solar energy. Among them, utilisation of solar energy by solar cell is an important and effective method and has a high potential in the commercial market. Based on the techniques and materials used to fabricate solar cell, the solar cells are classified into three generations. First generation solar cells are the larger, silicon based photovoltaic cells. The disadvantages of these solar cells are limited availability of silicon, requires expensive manufacturing technologies and higher energy photons are wasted as heat. The second generation solar cells are called thin film solar cells, which are significantly cheaper than previous generation cells but have lower efficiencies. The third generation solar cells are still in the research phase, but the results are promising and encouraging. Generally, third generation cells include nanocrystalline solar cells and dye sensitised solar cells, they do not have the p–n junction as in traditional solar cells. Third generation solar cells provide a technically and economically credible alternative concept to present day p–n junction solar cells. In the present study, the technology of the dye sensitised solar cell is introduced with a short description about the operating principle of the cell. After this, a more detailed study is carried out about the dye sensitised solar cell, taking into account the key steps involved in photovoltaic energy conversion and also the other important fundamental operational aspects of the solar cell physics and chemistry.