Structural and optical properties of ZnO films produced by a modified ultrasonic spray pyrolysis technique

• A variation of the ultrasonic spray pyrolysis (USP) technique is introduced.
• ZnO films were produced using the modification of the USP technique.
• High quality ZnO films were produced at a lower temperature than those used in other studies.

In this work we present a modification of the usual ultrasonic spray pyrolysis method and tested its ability to produce good quality films by producing ZnO films. Our method consists of keeping the sprayed substrate at room temperature and, after that, a thermal treatment under a chosen environment and temperature is made. We used this method to produce ZnO films considering two environments, air and air + vapor of zinc acetate, and two temperatures, 400 °C and 450 °C. The ZnO films were investigated by X-ray diffraction, scanning electron microscopy, cathodoluminescence, thermogravimetry/simultaneum differential thermal analysis and Raman spectroscopy techniques, and results indicated that ZnO films produced under air + vapor of zinc acetate at 400 °C are the best films obtained by our modified method.