Room-temperature photoluminescence evaluation of small-angle grain boundaries in multicrystalline silicon

The photoluminescence properties of small-angle grain boundaries (SA-GBs) with various misorientation angles were evaluated before and after Fe contamination. Comparison of SA-GBs with the same misohentation angle showed that the D-a1 band at 0.78 eV remain the same before and after the Fe contamination. At the SA-GBs with the misorientation angle of 5 degrees, a strong emission existed at 0.87 eV, which has been reported as an oxygen-precipitation-related peak. The emission of this high-energy region became weaker and shifted toward lower energy for a smaller misorientation angle. The high-energy emission became weak after the Fe contamination. It is considered that the Fe contamination affected the PL spectra originating from oxygen precipitates. (C) 2014 The Japan Society of Applied Physics