Electrical conduction mechanism in a-Se_80-xTe_xGa₂₀ films (0<or=x<or=20)

The dark conductivity and transient photoconductivity measurements on thin films of a-Se_80-xTe_xGa₂₀ (0<or=x<or=20) have been reported in the temperature range from 148 to 318 K. The results indicate that, at higher temperatures, hopping conduction takes place in the tail states. At lower temperatures the conduction is due to variable-range hopping, which is in fair agreement with the Mott condition of variable-range hopping. The transient photoconductivity measurements show non-exponential decay, and recombination in these glasses may be considered to take place through the valence and conduction bands.