Constant photocurrent spectra were obtained from a series of undoped multi-layers of amorphous hydrogenated Si on non-stoichiometric amorphous hydrogenated SiC. The SiC barrier layers had thicknesses which ranged from 0.5 to 10nm. It was found that the apparent defect absorption and the apparent Urbach energy in the constant photocurrent spectra increased monotonically with barrier layer thickness. The results showed that the interface properties were strongly affected by the barrier layer thickness. The interface defect density, as deduced from the constant photocurrent spectra, increased from 5 x 109 to 9 x 1011/cm2 with increasing barrier thickness.

F.Wang, T.Fischer, R.Schwarz: Applied Physics Letters, 1994, 65[22], 2798-800