Characterizing Recombination in CdTe Solar Cells with Time-Resolved Photoluminescence

Time-resolved photoluminescence (TRPL) computer simulations demonstrate that under certain experimental conditions it is possible to assess recombination in CdTe solar cells in spite of the junction. This is supported by experimental findings that open-circuit voltage (V_oc) is dependent on lifetime in a manner consistent with device theory. Measurements on inverted structures show that the CdCl ₂ treatment significantly reduces recombination in the CdTe layer without S diffusion. However, S diffusion is required for lifetimes comparable to those observed in high-efficiency solar cells. The results indicate that substrate solar cells can be fabricated with recombination lifetimes similar to superstrate cells