Ambiguous Influence of Radiation Effects in Solar Cells

Regardless of the very high standards in the production of electronic devices, all of them are more or less, prone to the effects of aging even if they are not exposed to extreme (hostile) working conditions. One of the most limiting factors for all kinds of detectors is their noise, such as frequency dependent generation-recombination noise, burst noise and 1/f noise. Common source of noise that is connected to the hostile working conditions is radiation. Photovoltaic (PV) conversion of solar energy is one of the most up-to-date semiconductor technologies that enables application of PV systems for various purposes. Solar cells, the basic elements for photovoltaic conversion of solar energy, are especially susceptible to radiation damage, primarily due to their large surface. The lifetime of the solar cell is restricted by the degree of radiation damage that the cell receives. This is an important factor that affects the performance of the solar cell in practical applications. Introduction of radiation-induced recombination centers reduce the minority carrier lifetime in the base layer of the p-n junction increasing series resistance, and lead to an enormous increase of noise in solar cells. After very high doses of radiation series resistance of the base layer could be so high that most of the power generated by the device is dissipated by its own internal resistance. The aim of this paper is to investigate the influence of radiation on output characteristics of solar cells in connection to their noise level that could lead to better understanding of transport properties, electron-hole pair creation etc.