H1electron-nuclear-double-resonance-detected ESR of light-soaked undopeda-Si:H

Highly resolved ESR spectra of undoped a-Si:H before and after light soaking have been measured over a wide dynamic range using ${}_{}{}^1{}_{}{}^{}\mathrm{H}$ electron-nuclear-double-resonance-detected ESR. All of the spectra show clear hyperfine structure between ${}_{}{}^{29}{}_{}{}^{}\mathrm{Si}$ and its dangling bond. The signal intensity of the ESR spectrum increases after exposure to standard solar AM-1 light, while the relative shape of the spectrum remains unchanged. The results are discussed in relation to the bond-breaking model.