Abstract
The electron affinity difference Delta E-c = chi(1)- chi(2) in CdS/CdTe solar cells fabricated by four different processes has been measured from observations of the variations of open voltages with temperature. For CdS/CdTe cells, the values of Delta E-c lie between 0.20 and 0.25 eV and are found to be independent of the process of cell fabrication. The use of CdZnTe in place of CdTe increases the value of Delta E-c to 0.49 eV. The method used for the measurement of Delta E-c is very simple. The values of the saturation current I-0 for the different types of cells have been estimated from the slopes of qV(oc) versus kT plots and compared with those obtained from InI versus V curves. The values of I-0 found for each cell by the two methods are in substantial agreement.