Structure study of cadmium tin oxide thin-films prepared by linear combinatorial synthesis

Thin films of transparent conducting cadmium tin oxide were produced by linear combinatorial synthesis using low-pressure metal-organic chemical vapor deposition. Different decomposition temperatures of Sn and Cd metal-organic precursors were used to achieve the composition variation. The structural properties varied with the composition along the gas flow direction, cubic CdO, spinel Cd₂SnO₄, amorphous, and finally the tetragonal SnO₂ structure was observed with the optical bandgap of the films increasing from ~2.7 to 3.65 eV. The highest electron mobility was achieved within the amorphous phase, at a composition range of Cd-to-Sn of 2-to-1~1-to-1.