Study of Electrical Transport Properties in Thermally Evaporated Cu2S Thin Films

Cu2S was synthesized by vacuum evaporation under a pressure of 10 - 6 torr at an evaporation rate of 3 angstrom/sec. The electrical properties of Cu2S thin film were studied using current-voltage characteristics. The conductivity was found to exhibit two distinct mechanisms within the applied field i.e., low voltage region and high voltage region. The most probable conduction mechanism prevailing in Cu2S thin film is found to be Poole-Frenkel effect. Activation energy has been calculated for different thicknesses and is found that activation energy decreases with increase in film thickness. Dielectric constant of the film was measured using impedance analyzer. Plot of dielectric constant vs. frequency shows normal dielectric behavior of the film. Photocurrent of Cu2S film increases with increase in film thickness.