Measurement of Solar Cell Parameters with Dark Forward I-V Characteristics

Abstract

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 defect levels in the band-gap, which act as generation-recombination centers or charge carrier traps. These levels influence the efficiency of solar cells. Therefore knowledge of the parameters of these levels, e.g., energy position, 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, namely measurements of dark characteristics. Preliminary results are introduced, together with the difficulties and limits of this method.