Conduction mechanism versus annealing in SiO2 films with Ge nanoparticles

This paper analyses and discusses the effect of Ge/Si atomic ratio and annealing temperature on the conduction mechanisms governing the electrical behavior of Ge-SiO₂ films containing Ge nanoparticles embedded in amorphous SiO₂ matrix. For this, the experimental conductance-temperature curves are modeled in correlation with the microstructure findings for two types of films. One type of films has a lower Ge/Si ratio of 0.73 and was obtained by magnetron sputtering followed by annealing in H₂, at 500 °C, while the second one has a higher ratio of 1.86 and was obtained also by sputtering, but was annealed in N₂, at 800 °C. Both types of films show an electrical behavior with a T^1/4 conductance dependence on temperature, typical for hopping mechanism.