Effect of nitrogen on structural stability of bismuth doped GeTe films under thermal treatment

We investigated the microstructures and electrical properties of 8.4% nitrogen-doped GeBi(6 at.%)Te and GeBi(6 at.%)Te films that were thermally annealed in air atmosphere. Despite annealing in air, GeBi(6 at.%)Te films showed only phase transition from cubic to rhombohedral phases. However, the Ge oxide, island shaped metallic Te, and Ge–Bi–Te phases were generated in 8.4% nitrogen-doped GeBi(6 at.%)Te films.

► We made and annealed GeBi(6 at.%)Te films with and without doped nitrogen.
► GeBi(6 at.%)Te films showed only phase transition from cubic to rhombohedral phases.
► Nitrogen-doped GeBi(6 at.%)Te showed severe oxidation.