ABSTRACT
Becquerel first discovered that sunlight can be converted directly into electricity in 1839, when he observed the photogalvanic effect. Solar energy became the obvious choice for alternative energy, either in the form of electricity via the photovoltaic (PV) effect or via solar thermal heating of water or other substances. But it would be necessary to significantly reduce the cost of capturing the solar resource before it could be used as a replacement for the relatively inexpensive fossil sources. Price, efficiency, performance, warranties, incentives, interest rates, money availability, space availability, and sometimes aesthetics have been the primary market drivers for current PV technologies. In fact, the decision to install generally involves consideration of all these factors. Semiconductor materials are characterized as being perfect insulators at absolute zero temperature, with charge carriers being made available for conduction as the temperature of the material is increased.
