Room-temperature luminescence and electron-beam-induced current (EBIC) recombination behaviour of crystal defects in multicrystalline silicon

Crystal defects such as dislocations and grain boundaries may show a detrimental influence on solar cell performance due to their recombination activity. The contamination of the defects by impurities strongly affects their recombination strength. Recently, it was shown that the temperature behaviour of the recombination activity of defects measured with EBIC, c(T), gives a quantitative access to the amount of contamination at dislocations. We have compared the mapping of the band-to-band and the defect (D1) photoluminescence (PL), measured at room temperature in multicrystalline Si, with the electron-beam-induced current temperature behaviour. Intensive D1 luminescence band and a remarkable reduction of the band-to-band PL intensity are observed at the defect sites. We have found that wafer regions with pronounced D1 band corresponds to dislocations with a weak contamination level down to a few tens of impurity atoms per μm of the dislocation length.