Optical absorption studies of ion implanted and amorphous silicon U. Zammit, K.N. Madhusoodanan, M. Marinelli, F. Scudieri, R. Pizzoferrato, F. Mercuri, E. Wendler and W. Wesch J. Phys. IV France, 04 C7 (1994) C7-113-C7-120 DOI: 10.1051/jp4:1994728