OPTICAL AND ELECTRICAL-PROPERTIES OF AMORPHOUS CU-RICH CU-GE-S FILMS - PHOTOINDUCED AND THERMALLY-INDUCED PHENOMENA

Photoinduced and thermally induced phenomena in Cu-rich Cu-Ge-S amorph ous alloys were examined. (Ge0.3S0.7)(100-x)Cu-x (0 less than or equal to x less than or equal to 65) films were prepared by co-evaporation of Ge30S70 glass and metallic Cu. Amorphous, homogeneous films were ob tained up to Cu contents of 62 at %. Photoinduced and thermal bleachin g of the optical absorption were observed in the composition range 0 l ess than or equal to x<40. Both types of bleaching decrease with incre asing Cu content and become negligible at around 40 at.%. The photoind uced surface deposition (PSD) of metal phenomenon was not observed eve n for the Cu-rich film of x=62. Optical and electrical properties of t he films were also examined as a function of Cu content and compared w ith the data for amorphous (Ge0.3S0.7)(100-x)Ag-x (0 less than or equa l to x less than or equal to 67) films. A difference between the Cu an d Ag systems is noticeable at metal contents above 25 at.%. It was fou nd that the Cu-rich films did not exhibit ionic conduction of Cu. The absence of the PSD phenomenon in the Cu-rich films can be accounted fo r by this lack of ionic conduction of Cu.