DISORDER AND THE OPTICAL ABSORPTION EDGE OF HYDROGENATED AMORPHOUS SILICON G.D. Cody, T. Tiedje, B. Abeles, T.D. Moustakas, B. Brooks and Y. Goldstein J. Phys. Colloques, 42 C4 (1981) C4-301-C4-304 DOI: 10.1051/jphyscol:1981463