The influence of Ge content and annealing temperature on the d.c and a.c conductivity of GexSe1 - x thin films

Authors : M F A ALIAS, M N Makadsi And Z M ALAJELI

Pages : 133-144

View : 17 | Download : 9

Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :Various samples of GexSe1 - x system have been prepared for x = 0.05, 0.15& 0.25 in an evacuated quartz tube. Thin films of GexSe1 - x film have been prepared via a thermal evaporation method with 350 \pm 5 nm thickness and rate deposition 6 nm/s. The alloy structure and thin films have been examined by X-ray diffraction insert ignore into journalissuearticles values(XRD);. Atomic absorption spectroscopy insert ignore into journalissuearticles values(AAS); was used to examine the concentration of the composite elements insert ignore into journalissuearticles values(Ge and Se);. The d.c and a.c conductivity of GexSe1 - x thin film have been studied as a function of Ge content x and annealing temperature within the range 303--448 K. Our results showed that the dc conductivity s of thin GexSe1-x films increases with increasing Ge content and decreases with increasing annealing temperature Ta. Electrical activation energy Ea decreases with increasing x values and increases with increasing annealing temperature. The a.c conductivity increases with increasing x values. The exponent s in the relation sa.c \propto ws, and which determines the transfer mechanism, decreases with increasing x and Ta. While the electrical a.c activation energy Ew increases with increasing x and Ta and at frequencies f = 102, 103 and 105 Hz. The relaxation time t and polarizibility a have been measured from the cole-cole plot for x = 0.05 at Ta = 303, 398 and 448 K, with the finding that the relaxation time and polarizibility decreased with increasing Ta.
Keywords : a c conductivity, d c conductivity, thin GexSe1 x film, dielectric constant