Solar energy is one of the most abundant and accessible sources of renewable energy available on earth. For many decades, scientists have been interested to find ways and means of harnessing the energy from the sun. Solar cells – often referred to as photovoltaic (PV) cells – provide a very attractive way to convert solar energy directly into electricity without affecting the environment. The most established solar cells available are silicon based solar cells (inorganic cells). They are widely used because of their high efficiency. However, they are rigid and manufacturing costs are high. Researchers have, therefore, focused on organic based solar cells to overcome these disadvantages. Such a type of solar cell is the dye sensitized solar cell (DSSC).
The principles of solar energy conversion will be described using the silicon based PV cells, which will help us understand the working principles of DSSCs. The main concepts are based on the movement of electrons between different atomic shells as they interact with incoming light.
• Atomic structure; covalent bonding; octet rule
• Redox reactions