A non-invasive approach was introduced for the investigation of grain boundaries in multicrystalline material. The technique was based upon the magnetic detection of photogenerated charge carriers which interacted with electrically active grain boundaries in the sample. The method was entirely non-destructive, and used highly sensitive superconducting quantum interference devices as detectors. Measurements were made of multicrystalline Si which had been fabricated using various methods. These revealed distinct features, of the magnetic signals, which were associated with characteristic material properties such as the excess carrier diffusion.

Photomagnetic Investigations of Grain Boundaries in Solar Silicon. J.Beyer: Semiconductor Science and Technology, 2001, 16[1], 44-53