Annealing temperature effect on structure and electrical properties of films formed of Ge nanoparticles in SiO2

- Films of Ge nanoparticles in SiO2 matrix were prepared by sputtering and annealing at 600-1000 °C.
- The film surface changes from a particle-like to a smooth one with the annealing temperature increase.
- Raman studies evidence Ge nanocrystals (NCs) in the films annealed at 700 °C.
- At 800 °C annealing, the strong Ge diffusion hinders Ge NCs formation.
- The transition from tunnelling to hopping mechanism by increasing the annealing temperature from 700 to 800 °C was evidenced and discussed.