Light and Elevated Temperature Induced Degradation in Gallium- and Boron-doped hpmc-Si Wafers Studied by Hyperspectral Photoluminescence Imaging

Light and elevated temperature induced degradation (LeTID) has been studied in both gallium- and boron-doped high performance multicrystalline silicon wafers. By using hyperspectral photoluminescence imaging as a characterization tool, we wanted to investigate the differences in the defect-related photoluminescence with respect to boron and gallium doping. The samples were first light soaked (0,16 suns) at room temperature, to activate boron-oxygen light induced degradation (BO-LID). To degrade and regenerate with respect to LeTID, the samples were illuminated with an intensity of 1 sun at 130 degrees C. The results shows that the gallium doped samples degenerates less and slower than the boron doped samples with respect the band-to-band (BB) signal. Almost all DRL follow the same pattern. But for the D3 signal, at 0.934 eV, the time scale is different. In the gallium doped samples, the degradation and regeneration of the D3 luminescence happens slower than for the band-to-band signal.