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Unformatted text preview: Giang Duong Student ID# 703708398 Chemistry 189 Instructor: Prof. R.B. Kaner Dec., 10th, 2008 Solar Panel I. Introduction& History of solar panels: A solar panel is composed of hundreds of photovoltaic cells, or solar cells, which absorb the solar energy and transfer it to usable electricity. Solar energy is one of the oldest types of energy in the earth, but human just discovered how to make the use of it since 1883 by Charles Fritts, who applied a semiconductor selenium layer on a thin surface of gold to create the junction. As a result, he created the first solar cell in the world, but its efficiency was only 6%. The solar cell’s applications were not efficiently used until after a nearly half-century later when Bell Laboratories accidentally discovered that silicon doped was more efficient than selenium in a solar cell. A discovery of silicon solar cell initiated a new era of solar cells, particularly the solar panels. Firstly, expensive solar cells were used as an alternative energy source for spacecraft during 1950s. Now as the photovoltaic technology becomes more efficient and cheaper, solar cells are widely used such as solar watches, solar calculators, solar autos, etc. and the solar panels are still being developed. The new record of solar cell’s energy conversion efficiency is 40.8% tested by the NREL (U.S. Department of Energy's National Renewable Energy Laboratory) and still keeps increasing potentially. II. Compositions and Operation of a single-junction crystal silicon photovoltaic cell: a. Single-junction Silicon photovoltaic cell’s composition: A solar panel is a flat panel composing of hundreds single solar cells. We can make a big single solar cell, but it will not be more efficient as a set of tiny solar cells. For instance, when a shadow covers on a part of a big solar cell, it will not generate electricity; but if we use a set of tiny solar cells on a panel, the other solar cells of the panel are still generating electricity in case a part of a solar panel is covered....
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- Fall '06
- pH, Solar cell, solar cells