Grain boundaries in silicon: microstructure and minority carrier recombination

The authors investigate the correlation between the microstructure and the minority carrier recombination of grain boundaries in thin silicon films solution grown with liquid phase epitaxy on cast silicon. We directly correlate electron beam induced current measurements with transmission electron microscope investigations identical grain boundaries in the epitaxial layers. The electrical recombination activity of grain boundaries may be caused or influenced by the microstructure, i.e. precipitates, dislocations and the atomic arrangement. Our investigations reveal that symmetric tilt boundaries show a much lower minority carrier recombination than asymmetric or microfaceted tilt boundaries.