Abstract: Ultrasonic irradiation technique was introduced to the traditional successive ionic layer adsorption and reaction (SILAR) method to modify the microstructure and crystallinity of ZnO films. ZnO nanocrystalline
porous films were successfully deposited on glass substrates from aqueous solution at 90℃ by using the precursor of [Zn(NH₃)₄]²⁺. Results show that as-deposited ZnO films exhibit excellent
crystallinity with the preferential orientation of (002) plane. A porous feature with interconnected particles of 200～400 nm in ZnO films was observed, and each ZnO particle formed is by the aggregation
of many crystallites in the size of 30～50nm. Because of the intense scattering function of the porous structure on the incident light, the films exhibit low transmittance in the visible band (～20%). With
the excitation of photon of 340 nm, an intense UV emission at 390 nm was observed in the PL spectra for as-deposited samples, indicating its good optical properties. The introduction of ultrasonic irradiation
in the film deposition process can exert significant effects on the structure and crystallinity of ZnO films.

Key words: ZnO, thin film, successive ionic layer adsorption and reaction （SILAR）, ultrasonic irradiation