Investigation on doping for maximum power extraction from a solar cell.

Nowadays, the research is being devoted to the development of rapid and precise maximum power point tracking for various photovoltaic applications. However the constraints imposed by size, cost, efficiency, and tracking performances essentially limit the application of conventional MPPT techniques and their analysis methodologies. This study gives us a complete picture of doping materials for Maximum power extraction from the solar cell (photovoltaic cell). As it is known that pure crystalline silicon atom is a poor conductor of electricity because none of its electrons are free to move about, unlike the electrons in more optimum conductors like copper. To overcome this, the silicon in a solar cell has impurities added – which are other atoms mixed in the silicon atoms. In general definition impurities are something undesirable, but this is not the case with the solar cell, which wouldn't work without them. The process of adding impurities is called doping, and when doped with phosphorous, the resulting silicon is called N-type because of the prevalence of free electrons. N-type doped silicon is a much better conductor than pure silicon. The other part of a typical solar cell is doped with the element boron, which has only three electrons in its outer shell instead of four, to become P-type silicon. Instead of having free electrons, P-type ("p" for positive) has free openings and carries the opposite (positive) charge. To improve the efficiency of the solar cell the use of processing techniques has to be found and implemented other than the processing of silicon and boron as all the manufacturers use this technique more widely. In general a mono module rated at 180W with an area of 1.28m2 may be 14.1% efficient while a poly module rated at 200W with an area of 1.47m2 may be 13.6% efficient. So the efficiency is only a measure of module output based on module area – the higher the efficiency the more power will be produced from the same size module or on the other way, the same output with fewer modules. This could be very important where available roof space is an issue. Energy is Wh, not just W so it is needed to consider weather factors such as strength of the sunlight, the amount of cloud cover and the ambient temperature. [ABSTRACT FROM AUTHOR]