Solar energy conversion


Energy and energy requirements present a serious problem for contemporary science and technology. Great expectations are put in the so-called solar batteries, which convert solar energy into electric one. This appears to be well justified, as each 1sec approximately 750 J energy falls (at vertical incidence) on each 1 m2 of the Earth surface. Its effective conversion into electric energy could be used to significantly improve the present-day power situation. It is practically only semiconductors that could be used as converters of this energy into the electric one, because they offer ideal conditions for light absorption. However, only absorption in itself would not solve the problem. If electromagnetic voltage is to be generated, the charge carriers, i.e. electrons and holes reliesed by the absorbed light have to be separated from each other. This task may be performed by an electric field existing in the PN junction, that is why a device with the PN junction appears to be a very suitable element from this aspect.