PHOTO-INDUCED REVERSIBLE CHANGE OF URBACH EDGE IN HYDROGENATED AMORPHOUS SILICON

Photoconductivity spectra temperature dependence combining with transmission measurements have been formed on hydrogenated amorphous silicon. After exposure by AM1 light a reversible increase of 6% of the Urbach parameter E₀ (T,X) has been observed. This is a direct evidence for the fact that photo-induced changes in a-Si:H create not only metastable defects but also affect the topological disorder.