Effect of Doping Mo Atoms on AZO (MAZO) Transparent Conductive Films

This study investigates the influence of high-valence molybdenum (Mo) doping on the optical, electrical, and mechanical properties of aluminum-doped zinc oxide (AZO) thin films. By incorporating an optimal amount of Mo, the surface defects of the MAZO films are significantly reduced, leading to enhanced crystallinity and film-forming quality. These structural improvements directly contribute to increased optical transmittance. In the MAZO films, Mo ions exist predominantly in high oxidation states of +5 and +6. Each doped Mo atom donates multiple free electrons to the lattice, resulting in a marked improvement in electrical conductivity. Additionally, the formation of highly polar Mo–O covalent bonds and the refinement of grain structures synergistically enhance the mechanical performance of the films─including hardness, elastic modulus, wear resistance, and creep resistance─thereby improving both mechanical stability and service life. As a result, MAZO films with outstanding photoelectric and mechanical performance have been successfully fabricated, achieving a low resistivity of 2.355 × 10–4 Ω·cm and a high optical transmittance of 89.0%. These findings demonstrate the potential of Mo-doped AZO films for high-performance optoelectronic and protective coating applications.