OPTICAL DEGRADATION OF A-SI-H FILMS WITH DIFFERENT MORPHOLOGY

The optical degradation (Staebler-Wronski (SW) effect) of a-Si:H films prepared by plasma CVD has been studied in connection with the morphological inhomogeneity of the films. The relative degradation rate of cubic photoconductivity alpha widely varied with deposition substrate temperature T//s and had its maximum at T//s equals 200 to approx. 250 degree C. In the films of both the lower and higher T//s, alpha decreased due to the increase of stable dangling bonds in the former and the decrease of weak bonds in the latter. The SW effect was hardly observed in mu c-Si:H deposited from highly diluted silane with hydrogen.