What is a Photovoltaic Cell
Solar energy, an important form of renewable energy, is being used extensively in solar water heaters and solar cookers. Solar energy is also being used on the large scale for generating electricity by using the devices called solar photovoltaic cells or solar cells or PV cells. Photovoltaic cells are devices that convert solar energy directly to electricity without the need of any other intermediary device. The first solar photovoltaic cells were made in the year 1950 and used in the US space satellites. At present photovoltaic cells are being in a wider range of devices from calculators to spacecrafts.
Construction of Solar Photovoltaic Cells
The construction material used for photovoltaic cells is silicon, a crystalline substance found easily on earth. To construct the photovoltaic or solar cell thin wafers of silicon are formed from its crystal. Two wafers of opposite electrical properties are joined together with wires to enable the flow of electrons between them.
When sunrays fall on photovoltaic cells the electrons start moving from one layer of silicon chip to the other layer in a natural manner because of the difference in properties of the two layers. The amount of electricity produced by the single photovoltaic cell is very small. Single solar cells are used in the devices that require a very small amount of electricity. These include calculators, small light bulbs, watches etc.
To increase the amount of electricity generated by the photovoltaic cells, the numbers of layers of the crystalline silicon in the photovoltaic cell are increased. These layers are joined together by the wires to form what is called as photovoltaic arrays.
It is the photovoltaic cells arranged in the form of arrays that find wide range of applications in our day-to-day life. The electricity generated from photovoltaic cells is stored in a battery. This electricity can be used in the homes and businesses for lights and other appliances, in street lights, billboards, emergency lights, solar lanterns etc.
Photovoltaic cells are presently also being used in the cars on experimental basis. Soon we will have the cars that will run on the renewable solar energy that won’t need expensive and pollution creating fossil fuels.