Role of stoichiometry and chemical composition in the properties of amorphous indium-based oxides

The main objective of this research is to understand how oxygen stoichiometry and chemical composition affect the structural and electrical properties of amorphous transparent indium-based oxides, obtained via first-principles molecular dynamics liquid quench approach. A detailed comparison of the structural properties (distribution of the metal-O and metal-metal distances, bond angles, and coordination) of crystalline oxides of post-transition metals and several amorphous In-X-O structures where 20% of indium atoms are replaced by specific metal X (Ga, Sc, La, or Y) and the number of oxygen atoms is adjusted to maintain or vary the stoichiometry and density in the sample was performed. In particular, in multicomponent amorphous In-X-O, the presence of X may alter the number of octahedrally coordinated In atoms and result in the appearance structural defects responsible for carrier generation. The results may help explain the observed intriguing behavior in the carrier concentration as a function of the substitution level in amorphous In-X-O