Investigation studies of pure and molybdenum doped zinc oxide thin films deposited by spray pyrolysis technique for transparent conductive oxides applications

Pure and molybdenum doped zinc oxide thin films, with different Mo doping concentrations, have been deposited on cleaned glass substrate, at temperature 450 °C using spray pyrolysis technique. The structural, morphological, chemical compositions, optical and electrical properties of the prepared films were investigated. Structural analysis of the XRD patterns revealed that the pure and Mo doped ZnO thin films were polycrystalline in nature with hexagonal wurtzite structures and had a (0 0 2) plane orientation. The Surface morphology of the prepared thin films obtained by SEM images revealed that the agglomeration of grains was porous, which is useful for photovoltaic applications. Moreover, AFM observations revealed that the particle size and surface roughness of the prepared films decreased with increasing Mo doping. Optical measurements indicate that the band gap decreases with increasing Mo doping, that all the prepared films are transparent in the visible region, and that the transmission is high for 6 at % of Mo doped ZnO. The PL studies showed that the maximum intensity of the UV emission band was 6 at% Mo, Which indicated an improvement in crystallinity. Electrical measurements revealed that a minimum resistivity of 6 at% of Mo-doped film was 1.20 × 10⁻³ Ω cm with increasing hall mobility, carrier concentration and conductivity. These results indicate that Mo-doped ZnO is a suitable material for TCO applications.