Using a combination of positron annihilation and x-ray-diffraction techniques, we have shown that low hydrogen concentration hot wire chemical vapor deposition grown a-Si:H forms a continuous random network with no detectable free volume in the form of microvoids, and no evidence of a microcrystalline phase. On annealing up to 400 °C, the amorphous network is seen to relax and the first stages of recrystallization occur. There is also evidence of vacancy clustering to form a low concentration of microvoids. The structural relaxation has a very low activation energy, around 0.1 eV, and is probably caused by a reconfiguration of hydrogen-terminated dangling, bond defects. The formation of microvoids and the recrystallization can both be interpreted by the migration of unterminated dangling-bond defects.
|Number of pages||8|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 15 Aug 2001|
ASJC Scopus subject areas
- Condensed Matter Physics
- Electronic, Optical and Magnetic Materials