High Resolution NMR Studies of Different Hydrogen Sites in Amorphous Hydrogenated Silicon

摘要

Amorphous silicon must be hydrogenated to cure its dangling bonds, thus allowing doping and photovoltaic effect. However, hydrogenated amorphous silicon (a Si:H) contains typically 15% H per Si, i.e. which is more concentrated in hydrogen by two orders of magnitude than necessary to cure the defects. The role played by hydrogen in the structure of a Si:H is studied. High resolution NMR of protons with Magic Angle Spinning (HR NMR-MAS) of the sample. Three kinds of different states of the protons are resolved spectroscopically. The clustered protons corresponding to the broad line in the usual proton NMR spectra diluted protons in the amorphous structure and H sub 2 molecules contained in microvoids, which both contribute to the narrow line in the usual NMR spectra. (ERA citation 11:004032)