Modification of microstructure and optical properties of ZnO thin films deposited by spray pyrolysis

Keywords

thin films, spray pyrolysis, band gap energy, optical transmission.

Cite as

Maldonado R. D., Bilyy O. L., Martínez-Zaldivar J. M., Tamayo-Loeza E. J., Mézquita-Martínez R. S., May-Cen I., Metelin-Rosado I., Pintos-Díaz G. A., and Alonzo-Medina G. M. Modification of microstructure and optical properties of ZnO thin films deposited by spray pyrolysis. Physicochemical Mechanics of Materials. 2026. 62(2), 122-127.

https://doi.org/10.15407/pcmm2026.02.122

Abstract

The effect of the mixing time of the precursor solution on the microstructure and optical properties of ZnO thin films obtained by the spray pyrolysis method was investigated. The films were deposited on glass substrates preheated to 400C using an inexpensive automated system. It was found that varying mixing time (1–40 h) significantly affects the surface morphology, crystal structure, and optical characteristics of the films. Scanning electron microscopy results revealed a surface evolution from a porous structure with he¬xagonal grains to a more homogeneous one with rounded grains with increasing mixing time. The X-ray diffraction results confirm the formation of a wurtzite crystal structure with a predominant (002) orientation, the intensity of which decreases with increasing mixing time. An increase in the transmittance to 80% and an increase in the band gap from 3.02 to 3.21 eV was established. The results obtained indicate the possibility of controlling the properties of ZnO films by adjusting the conditions of the precursor solution preparation, which opens up prospects for their application in optoelectronics and sensor devices.

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