Defect Analysis in Solar Cell Silicon by Photoluminescence Spectroscopy and Topography

Abstract

We review the characterization of electrically active intra-grain defects in multicrystalline silicon for solar cells. Origin of the defects was identified to be dislocation clusters forming subgrain boundaries by photoluminescence (PL) spectroscopy and topography combined with electron backscatter diffraction pattern measurement and etching/optical microscopy. PL imaging during HF etching has the advantage of very rapid detection of defects, which allows us to obtain numerous successive PL images of wafers positioned from the bottom to top of the mc-Si ingots, as well as to synthesize the three-dimensional distribution of the defects from the images. We showed the multiplication of dislocation clusters and their interaction with grain boundaries.