Hydrogen distribution in the vicinity of dangling bonds in hydrogenated amorphous silicon (a-Si: H)

We have investigated the distribution of H atoms around native dangling bonds in a-Si:H by electron-nuclear double resonance (ENDOR). In contrast to previous electron spin echo envelope modulation (ESEEM) studies [Isoya et al., Phys. Rev. B 47(12), 7013-7024 (1993)] we find that the distance between H atoms and dangling-bond defects can be well below r = 3Å . Our experimental data suggest that the H distribution is continuous and homogeneous and there is no indication for a short-range order between H atoms and dangling bonds. This work is a first step toward the investigation of the H distribution around lightinduced defects to test models predicting the immediate proximity of H and defects.