Frequency dependent capacitance studies of the CdS/Cu2S thin-film solar cell

Measurements of the dark capacitance of CdS cells as a function of the frequency of the applied signal voltage have shown that the capacitance varies with frequency according to the relation C−C∞ = (C0−C∞)/(1+ω2τ2), where τ is the time constant associated with interfacial and deep bulk states. Photocapacitance studies show that the CdS cell can be treated according to the frequency dependent model of Schibli and Milnes. Under the influence of light, C∼1/(ω)1/2. Further work demonstrates that the simple planar junction model most often used to describe the CdS cell is accurate at high frequencies.