Determination of recombination centres in c-Si solar cells from dark I-V characteristics

The grade of a solar cell depends mainly on the quality of the starting material. During the production of this material, many impurities are left in the bulk material and form defects, which act as generation-recombination centres or charge carrier traps. These defects influence the efficiency of solar cells. Therefore knowledge of the centre parameters, e.g., energy levels in the band gap, capture cross section and concentration, is very useful for solar cell engineering. In this paper emphasis is placed on a simple and fast method for obtaining these parameters using measurements of dark characteristics. Preliminary results are introduced, together with the difficulties and limits of this method.