Structural and Electronic Properties of Amorphous and Polycrystalline In2Se3 Films

TL;DR

This study investigates the structural and electronic properties of amorphous and polycrystalline In2Se3 films, revealing phase-specific nucleation behaviors, resistivity differences, and the effects of annealing and preparation conditions on their properties.

Contribution

It provides detailed analysis of the microstructure and electronic characteristics of In2Se3 films, highlighting differences between amorphous and crystalline phases and effects of processing.

Findings

Gamma phase nucleates homogeneously with high resistivity.

Kappa phase nucleates at the surface with moderate resistivity.

Annealing increases resistivity due to bond replacement.

Abstract

Structural and electronic properties of amorphous and single-phase polycrystalline films of gamma- and kappa-In2Se3 have been measured. The stable gamma phase nucleates homogeneously in the film bulk and has a high resistivity, while the metastable kappa phase nucleates at the film surface and has a moderate resistivity. The microstructures of hot-deposited and post-annealed cold-deposited gamma films are quite different but the 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.