Investigation Studies of Pure and 2, 4, 6 & 8 at.% of Molybdenum Doped Zinc Oxide (ZnO, Mo-ZnO) Thin Films Deposited by Spray Pyrolysis Technique for Transparent Conductive Oxides (TCO) Applications

Abstract Pure and molybdenum doped zinc oxide (ZnO, Mo-ZnO) thin films have been deposited on cleaned glass substrate at temperature 450°C using spray pyrolysis technique at different Mo doping (2, 4, 6 & 8 at.% ) concentrations. These films have been analyzed in structural, surface morphological, surface roughness, chemical compositions, optical and electrical studies. Structural analysis in XRD patterns provides that the pure and Mo-ZnO thin films were polycrystalline nature with hexagonal wurtzite structure and has a (0 0 2) plane oriented direction. Surface morphology of the prepared thin films obtained by SEM images provides that the agglomeration of grains with the porous nature which is useful for the photovoltaic applications. AFM observations exposed that the particles size and surface roughness of the prepared films decreased with Mo doping of films increased. Optical measurements indicate that the band gap was decreased with increase in Mo doping and all the prepared films are transparent in visible region, transmission is high for 6 at. % of Mo doped ZnO. The PL studies provides the maximum intensity of UV emission band is 6 at.% Mo content, it shows the improvement of crystallinity. Electrical measurement results provides that the minimum resistivity of 6 at. % of Mo doped film was 1.20 x 10⁻³Ω cm with increase in the hall mobility, carrier concentration and conductivity. These results make Mo-doped ZnO using a good suitable material for TCO applications.