Published online by Cambridge University Press: 01 February 2011
We have investigated the localized electronic states in mixed-phase hydrogenated nanocrystalline silicon thin films (nc-Si:H) with electron-spin-resonance (ESR). The dark ESR signal most likely arises from defects at the grain boundaries or within the crystallites. With illumination with photon energies ranging from 1.2 eV to 2.0 eV, there is no evidence of photo-induced carriers trapped in the bandtail states within the amorphous region. Dependence of the light-induced ESR (LESR) upon the exciting photon energy reveals that, at different excitation photon energies, different regions dominate the optical absorption. This behavior may have potential consequences for understanding the light-induced degradation in nc-Si:H.