Photographic distinction of defects in polycrystalline Si by spectroscopic electroluminescence

By using spectroscopic EL imaging technique, the intrinsic defects and the extrinsic deficiencies can be distinguished clearly at a glance. The intrinsic defects with deep traps induce infra-red emission depending on the electronic trap level. By comparing the filtered images, extrinsic defects which may cause serious effect on long term reliability can be detected photographically.