Current–voltage characteristics and quantum efficiency spectra of efficient thin-film CdS/CdTe solar cells

• The I–V characteristics of CdS/CdTe solar cells are described in terms of the Sah–Noyce–Shockley theory.
• The expressions for the quantum efficiency spectra also describe the observed spectra in detail.
• Comparison of the calculation results with the experimental data provides a determination of the main parameters of the CdTe layer.

A comparison of the calculated results with the experimental data shows that the measured dark I–V characteristics of efficient thin-film CdS/CdTe cells are quantitatively described in terms of the Sah–Noyce–Shockley theory of generation–recombination in the space-charge region of the heterostructure. The expressions for the quantum efficiency spectra, taking into account the drift and diffusion components and recombination on the front and rear surfaces of the CdTe absorber layer, also describe the observed spectra in detail. The process of comparison and adjustment of the calculated results with the actual measurements provides a quite accurate determination of the main parameters of the CdTe layer and the diode structure, which in turn enables us to make some recommendations to correct these parameters to increase the efficiency of CdS/CdTe solar cells.