Abstract
Thin films of Ga
x
Te
100−
x
(x = 3, 6, 9 and 12) have been synthesized by thermal evaporation. From SEM images, it is observed that all the films contain nanoparticles of sizes varying from 100 to 200 nm. The dc electrical conductivity of the as-deposited films of Ga
x
Te
100−x
nanoparticles is measured as a function of temperature range from 298 to 383 K, and increases exponentially with temperature. The value of the activation energy, calculated from the slope of ln σ
dc
versus 1000/T plots, is found to decrease with increase in the Ga content. On the basis of the value of the pre-exponential factor σ
o
, it is suggested that the conduction is due to thermally assisted tunneling of carriers in localized states near the band edges. The optical measurements suggest an indirect optical band gap in this system. The value of the optical band gap decreases on increasing the Ga concentration.