Interior and Surface Degradation Analysis of Multicrystalline Si Solar Cell Module Using Laser-Beam-Induced Current Technique

The interior and surface degradation of a multicrystalline silicon (mc-Si) solar cell module was investigated using the laser beam-induced current (LBIC) technique. Reverse voltage was applied to avoid the influence of the solar cells not irradiated with light and to evaluate the LBIC intensity only of the illuminated solar cell. In addition, we found that the mc-Si, but not the solar cell surface, is comprised of homogeneous crystals and the degraded layer is estimated to be
$\sim 0.6~\mu\text{m}$
. The LBIC technique was applied at several wavelengths under reverse bias conditions in order to analyze degraded solar cells.