BULK MINORITY CARRIER LIFETIME FROM LUMINESCENCE INTENSITY RATIOS MEASURED ON SILICON BRICKS

摘要

Bulk lifetime measurements on silicon bricks based on the ratio of two photoluminescence images taken with different spectral filters in front of the camera are demonstrated. This new method allows bulk lifetime to be measured with high lateral spatial resolution and with measurement times that are compatible with production throughput. Compared to a previous photoluminescence imaging measurement technique that is based on the analysis of the absolute luminescence intensity in a single luminescence image the methodology presented here is advantageous as it does not require a separate resistivity measurement for normalisation of the measured luminescence intensity and avoids related experimental inaccuracies. Since this new method relies on the analysis of an intensity ratio between two luminescence measurements it is also less sensitive to long term drifts in experimental parameters such as the intensity or uniformity of the external illumination. Experimental results on industrial boron doped multicrystalline silicon brick are presented and compared to experimental data from previous studies.