Effect of Annealing Temperature on the Resistivity of Zinc Oxide Films Deposited by Spray Pyrolysis
Emmanuel A. Florido1*, Golda Filipina B. Gianan1
1Institute of Mathematical Sciences and Physics, University of the Philippines Los Banos, Los Banos, Laguna, Philippines
* Presenter:Emmanuel A. Florido
Spray pyrolysis was used to deposit zinc oxide (ZnO) films on glass substrates using a precursor solution which consisted of zinc acetate dihydrate (Zn (CH3COO)2· 2H2O) dissolved in deionized water at 0.2M concentration. An atomizer was used to spray the solution with nozzle vertical distance of 20 cm from three glass substrates placed side by side and maintained at 3000C. Spraying of the solution was done intermittently with a spray time of 1 second and 5 seconds interval. The total deposition time was 30 minutes. Three fabricated films were annealed at different temperatures of 3000C, 4000C, and 5000C, respectively.

The presence of zinc oxide was confirmed by energy dispersive spectroscopy (EDS). The test also showed that the oxygen content decreased with increasing annealing temperature. Scanning electron microscopy (SEM) revealed the granular structure of the films and further showed a fusion of the grains at 5000C.

Four-point probe technique was used to obtain the I-V (current-voltage) plot from the ZnO film. Results showed a decrease in resistivity of 0.1142 MΩ·m, 0.0949 MΩ·m, and 0.0128 MΩ·m for the annealing temperatures of 3000C, 4000C, and 5000C, respectively due to the fusion of the grains at higher annealing temperature as revealed by the SEM results.

Keywords: zinc oxide, spray pyrolysis, resistivity, annealing