Conduction studies on bismuth selenide thin films

Thin films of Bi 3 Si 3 have been prepared by vacuum deposition technique onto well cleaned glass and freshly cleaved KBr substrates. The film thicknesses are measured by Tolansky technique. The capacitance and dielectric constant have been measured from 303 K to 383 K in the frequency range of 10 kHz to 10 MHz, The a.c. conductivity σ is calculated at different frequencies for various temperatures. The relation σ ω 1 fits well and the value of n is found to be greater than 1.5 and above at high frequencies suggests that the conduction mechanism in Bi 2 Se 3 thin fil is hopping. The d.c. conduction studies revealed the non-ohmic type of conduction Log 1 versus Log V plot). From the Log 1 versus F 2 plot, the field lowering coefficient β is evaluated.