Solar Cell

The scale of solar energy is quite wide and its intensity varies according to the timing of the day and the geographical location of the country. In India the sun first rises in the Arunachal Pradesh, so the intensity of sunlight in Arunachal Pradesh is more than in comparison of other states of India. This is applied all over the world. In this paper applications and generations of solar cells are discussed. Solar cells and photovoltaic cells are devices that convert light direct into electricity. A solar cell is an example of a photovoltaic device, i.e, a device that generates voltage when exposed to light. The functioning of a solar cell is similar to the photodetector cell. It is a photodiode that is unbiased and connected to a load. There are three qualitative differences between a solar cell and photodetector. 1) A photodiode works on a narrow range of wavelength while solar cells need to work over a broad spectral range (solar spectrum). 2) Solar cells are typically wide area devices to maximize exposure. 3) In photodiodes the metric is quantum efficiency, which defines the signal to noise ratio while for solar cells, it is the power conversion efficiency which is the power delivered per incident solar energy. 4) Concentrated photovoltaic technology (CPV) uses optics such as mirrors and lens to focus sunlight on solar cells for the sake of generating electricity.