Influences in high quality zinc oxide films and their photoelectrochemical performance

Abstract

Transparent conductive zinc oxide thin films have been synthesized by spray pyrolytic decomposition of aqueous solution of zinc acetate onto the corning glasses with different pre-heating temperatures. The influence of pre-heating temperature on the structural, morphological, optoelectronic and electrical properties is investigated. The X-ray diffraction patterns revealed the polycrystalline nature with hexagonal (wurtzite) crystal structure. Films show preferred c-axis orientated with (0 0 2) growth. Films deposited at various deposition temperatures exhibit different surface morphologies. It is observed that the temperature plays an important role in modifying surface morphology and size of crystallites. Compact hexagonal platelets like structure is observed for lower temperature samples. The films exhibit nanoparticles of size 60–100 nm for 250–500 °C temperatures. Films are highly transparent and conducting, we achieved 95% transmittance at 550 nm with electrical resistivity 0.062 Ω cm and figure of merit 7.88 × 10 −4 □/Ω. Moreover samples are photoelectrochemically active and exhibit the highest photocurrent of 212 μA, a photovoltage of 353 mV and 0.32 fill factor for the 450 °C films.