Case Study of Solar Cells

Solar cells or photovoltaic cells are a renewable source of electricity, harnessed from sunlight and thermal energy derived from the sun. It doesn’t emit any greenhouse gases (sulphur dioxide and carbon monoxide) when producing electricity. During a sunny and clear day, sun rays can provide over a 1000 watts of energy per square meter of the planet’s surface. Photovoltaic cells are made of semi conductive material such as silicon. As the light ray hits the solar cell, a fraction of the light is absorbed within the semi conductive material. The energy from the light knocks electrons loose causing them to collide, becoming delocalised. Solar cells can be used as a partial or entire source for energy, it allows the consumer to reduce energy costs and save money, the only issue being that due to installation costs, the payback time for solar power could be several years.
Photovoltaic cells use a single junction to create an electric field within the semi conductive silicone. Within a single junction Photovoltaic cell, only the photons which an equal amount of energy or greater than the band gap (energy range in solid material where no exist) of the material can delocalise an electron to for an electric circuit. To convert more energy from the photons, more solar cells are used to create plural band gaps and junctions. Devices with multiple junctions (tandem cells) have a higher conversion efficiency, wasting less energy in the process, due to a converting more energy derived from the photon.
It does this by creating an electrical imbalance, which is caused by disrupting the structure of the silicon material. The silicon is arranged in a tightly bonded lattice, by squeezing small quantities of other elements into the structure. Then two different types of silicon material are created, negative type (negative charge and spare electrons) and