Temperature-dependent quantum efficiency measurements were used to investigate recombination in epitaxial Si thin-film solar cells grown by ion-assisted deposition. Analysis of the experimental results unveils that the diffusion length in this material was dominated by Shockley–Read–Hall recombination via relatively shallow defects with activation energies of 0.070 to 0.110 and 0.160 to 0.210eV. The device performance at room temperature was controlled by the concentration of the deeper one of those two defects. The temperature-dependent quantum efficiency method proves to be a reliable variation of lifetime spectroscopy allowing for the quantitative identification of recombination active defects in completed solar cells.

Analysis of Recombination Centers in Epitaxial Silicon Thin-Film Solar Cells by Temperature-Dependent Quantum Efficiency Measurements. T.A.Wagner, U.Rau: Applied Physics Letters, 2003, 82[16], 2637-9