The photo –voltaic effect can be observed in nature in a variety of materials but the materials having the best performance in sun light are the semi conductors. When photons of the sun light are absorbed in a semi –conductor, they create free electrons (and holes) with higher energies than the electrons which provide the bonding in the crystal. Once these free electron holes to flow pairs are created, there must be an electric field to induce these higher energy electrons and holes to flow out of semi conduction to do useful work. In typical solar cell this is done by the use of p—n junction. It is known that an electric field exists across a p—n junction and this field sweeps the electrons in one direction and holes in the other. so these are basic working of photo-voltaic cell.
In this article we will know about the photo-voltaic cell working and their application . we will know brief working of photo-voltaic cell.
Photo-Voltaic Cell working
It is possible to covert solar energy directly into electric energy by photo-voltaic process. The photo-voltaic effect is the generation of an EMF as a result of the absorption of ionizing radiation. Energy conversion devices which are used to convert sunlight to electricity by photo-voltaic effect are known as photo voltaic cells. Thus a solar cell is a transducer which converts the sun’s radiant energy directly into electricity and is basically a semi conductor diode capable of developing a voltage of 0.5 -1v and a current density of 20-40mA per 2cm depending on the materials used and the sun light conditions.
A typical solar cell is shown in diagram. active area of solar cell is less than full front surface area because of the need to position opaque conductors on top the cell to collect the generated current. Practical top contact structure are generally in the form of comb to like grids so designed as to strike a balance between reduced active area and reduced series resistance brought about the increasing the contact coverage. An anti reflection coating is often employed to improve the coupling of light into the semi-conductor. The solar cell has to be encapsulated to protect it from atmospheric degradation.so it is overall working of photo voltaic cell. for better know about photo-voltaic cell we must need to know about working of solar cell.
Many types of solar cells have been proposed. The two types available commercially are single crystal silicon cells and cadmium sulfide/cumbrous sulfide cells. Single crystal silicon is the most highly developed material for photo voltaic conversion. The physical properties of single crystal silicon are well understood and the raw material is abundant. Single crystal silicon cells have efficiency around 10to 14 per been used for many years as power sources for space craft in sizes from a few watts to over 20KV per satellite. However they are still very costly and many attempts have been initiated in France, Japan, USA, West Germany etc. to reduce the cost.
Hence these are photo-voltaic cell working if you will find any incorrect in above article you must comment below in comment box. thanks
If you want to know more about the photo voltaic cell working you must sea this video.