HIGH-ENERGY ION-IMPLANTATION INDUCED ELECTRICAL EFFECTS IN BULK AMORPHOUS AS2SE3

Bulk amorphous chalcogenide semiconductor: As2Se3, has been irradiated at room temperature with 75 MeV energy Ni, Ge and Ag ions at fluences in the range 1 x 10(13)-1 x 10(14) ions/cm(2). The ion-induced effect s on the electronic properties have been monitored by measuring the de conductivity and frequency dependent ac conductivity (500 Hz - 10 kHz ) as a function of temperature (180-450 K). It is found that the elect rical effects in the samples bombarded with Ni ions are quite differen t from the ones bombarded with Ge/Ag ions. Ion-irradiation induced def ect states near the Fermi level play a dominant role in the variable r ange hopping conduction. Bipolaron hopping conduction appears to be af fected less by ion-irradiation. It is interesting to see that as small an ion-dose as 5 x 10(13) ions/cm(2) is quite effective to modify the electrical transport behaviour of the glass. (C) 1998 Elsevier Scienc e B.V.