Structure,composition and optical properties of ZnO:Ga films electrodeposited on flexible substrates

Thin films of ZnO:Ga are electrodeposited on stainless steel from zinc chloride solutions containing gallium with a Ga/Zn molar ratio in the range 1–10%. The surface morphology, structure, composition, and the optical properties of these films are studied using SEM, XRD, EDX, XPS, photoluminescence and transmittance spectroscopy. Results reveal that films with embedded platelets can be grown with a Ga/Zn molar ratio up to 60%. In as-grown films, Ga is present in the form of oxide, hydroxide or hydroxychloride compounds which decompose by annealing. Films annealed at 400°C are composed only from ZnO and Ga₂O₃ phases. The incorporation of Ga in ZnO films does not make a considerable change in the optical transmittance and the photoluminescence properties of the films.