Electrical transport properties of thin films of a-Se 80 – x Ga 20 Bi x

Dark conductivity measurements on thin films of a-Se_{80 – x} Ga₂₀ Bi_x (where x = 0, 5, 10, 15, 20) are reported in the temperature range 148–318 K. The results indicate that at higher temperatures (287–318 K), the conduction occurs in the band tails of localised states and at lower temperatures (148–287 K) the conduction is due to variable range hopping, which is in reasonable agreement with Mott's condition of variable range hopping conduction.