Heon Lee

Structural and electronic properties of amorphous and polycrystalline In2Se3 films

Structural and electronic properties of amorphous and single-phase polycrystalline films of γ- and κ-In2Se3 have been measured. The effect of deposition conditions on the film phase was studied extensively. The stable γ phase nucleates homogeneously in the film bulk and has a high resistivity, while the metastable κ phase nucleates at the film surface and has a moderate resistivity. The microstructures of polycrystalline hot-deposited and postannealed, cold-deposited γ films are quite different but their electronic properties are similar. The increase in the resistivity of amorphous In2Se3 films upon annealing is interpreted in terms of the replacement of In–In bonds with In–Se bonds during crystallization. Great care must be taken in the preparation of In2Se3 films for electrical measurements as the presence of excess chalcogen or surface oxidation may greatly affect the film properties.