Analysis of recombination centers in epitaxial silicon thin-film solar cells by temperature-dependent quantum efficiency measurements

Temperature-dependent quantum efficiency (TQE) measurements are used to investigate recombination in epitaxial silicon thin-film solar cells grown by ion-assisted deposition. Analysis of the experimental results unveils that the diffusion length in this material is dominated by Shockley–Read–Hall recombination via relatively shallow defects with activation energies of 70–110 and 160–210 meV, respectively. The device performance at room temperature is controlled by the concentration of the deeper one of those two defects. The TQE method proves to be a reliable variation of lifetime spectroscopy allowing for the quantitative identification of recombination active defects in completed solar cells.