Structural and electrical properties of Al and B Co-doped Zno thin films

In this work, Al and B were co-doped in ZnO as donors, and the electrical and optical properties of the thin films were investigated. Since B ions easily evaporate during target sintering a compound of Al₄B ₂O₉ was prepared and doped in ZnO. The thin films were grown on glass substrates via the RF magnetron sputtering method. The crystal structure of the thin films was found to have a polycrystalline hexagonal wurtzite structure, and the films were grown with a c-axis preferred orientation. The lattice constant of the films decreased and then increased as the dopant concentration increased, which suggests that the defect structure has changed from substitutional to interstitutional at a critical dopant concentration. The optical transmittance and electrical characteristics were also examined.