Growth of multifunctional ZnO thin films by spray pyrolysis technique

• Synthesis of ZnO thin films onto glass substrates at 450 °C from aqueous zinc acetate solution.
• The multifunctionality of spray deposited ZnO thin films was investigated.
• Gas sensing performances toward three gases (ethanol, propanol and acetone) were investigated.

Simple and economical spray pyrolysis technique (SPT) was employed for synthesis of multifunctional zinc oxide (ZnO) thin films onto glass substrates. The synthesized material was composed of Zn2p and O1s, as confirmed from X-ray photoelectron spectroscopy (XPS). Field emission scanning electron microscopy (FESEM) image revealed the uniform distribution of grains of about 80–90 nm. The film shows superhydrophobic nature with contact angle (CA) value 154°. The deposited film was specular and highly transparent with average transmittance of about 85%. The optical transmittance spectrum shows sharp band edge at 381 nm, corresponding to band gap energy of 3.25 eV. Film exhibits room temperature photoluminescence (PL) with a strong ultraviolet emission at 398 nm with weak green emission at 520 nm, confirms the less defect density in the samples. The gas sensing performance of the spray deposited ZnO films toward to reducing gases like ethanol, propanol and acetone was also studied. We examined here the viability of SPT in order to deposit such multifunctional ZnO thin films on glass substrates, which can be useful for various applications.