ALLOYING EFFECTS ON THE OPTICAL ABSORPTION EDGE AND PHOTOCONDUCTANCE OF RF SPUTTERED a-Sn//xSi//1// minus //x:H FILMS.

Hydrogenated amorphous Sn-Si alloy films were prepared by reactive co-sputtering at 220 and at 110 degree C. The tin content of the films varied between 0. 3 and 4. 7 at. %. The optical absorption and photoconductivity were measured as a function of wavelength and film composition. The energy gap, as evaluated from these measurements, decreases with increasing tin content, more strongly for samples prepared at the lower temperature. The photoconductance response varies strongly, by about three orders of magnitude, as the Sn concentration increases to 4. 7 at. % and is quite different for the two kind of samples.