Model for the frequency-dependence of the capacitance in CdSCu2S solar cells

It is shown, theoretically and experimentally, that deep donor levels play an important part in the structure of the space charge region of CdSCu₂S solar cells. Both in the dark and under illumination, they are responsible for the frequency dependence of the capacitance, although their role in the compensation mechanism of diffused Cu-acceptors is different in both situations. These levels lie at about 0.5 eV under the conduction band, they show a spread in energy of about 0.2 eV, and have response times in the range of 10^?2 to 10^?6 sec.