The interfacial states in the band-gap and potential barrier associated with grain boundaries in polycrystalline Si could exert their detrimental influence on electrical conductivity and then on device performance. However, all grain boundaries were not similarly potential sites for electrical activity because individual grain boundaries have their own character depending on the orientation relation between two adjoining grains. The electron-beam-induced current technique and the Kelvin probe force microscopy were used to observe the carrier recombination intensity and the potential barrier height, respectively, at well-characterized grain boundaries in semiconductor-grade polycrystalline Si. The results were compared with the previously observed ones in solar-grade Si to examine the factors affecting electrical activity of grain boundaries.

Interfacial State and Potential Barrier Height Associated with Grain Boundaries in Polycrystalline Silicon. S.Tsurekawa, K.Kido, T.Watanabe: Materials Science and Engineering A, 2007, 462[1-2], 61-7