Photo-induced changes in the bulk density of gap states in hydrogenated amorphous silicon associated with the Staebler-Wronski effect

✍ Scribed by J.David Cohen; David V. Lang; James P. Harbison; A.M. Sergent

• Publisher: Elsevier Science
• Year: 1983
• Weight: 752 KB
• Volume: 9
• Category: Article
• ISSN: 0379-6787
• DOI: 10.1016/0379-6787(83)90081-9

✦ Synopsis

We observe a reversible photo-induced modification in the bulk density of gap states in hydrogenated amorphous silicon associated with the Staebler-Wronski effect. Detailed analysis of deep level transient spectroscopy, admittance and thermally stimulated capacitance measurements indicates that as a result of prolonged illumination (1) a lowering of the bulk Fermi level occurs in the mobility gap, (2) a large increase occurs in the density of states below midgap and (3) no discernible change occurs in the midgap defect density normally associated with dangling bond defects. In addition we find that the annealing behavior of the light-induced effects indicates a broad range of activation energies. A comparison of these findings with measurements made by other groups is discussed briefly.