Effect of Au and Ag nanoparticles addition on the morphological, structural and optical properties of ZnO thin films deposited by sol-gel method

Abstract

In the present study, ZnO thin films were deposited on quartz substrates by sol-gel spin-coating method. Zinc-diacetate ((Zn(CH3COO)2.2H2O), diolamine (DEA) (HN(CH2CH2OH)2) and ethylene glycol monomethyl ether (CH3OCH2CH2OH) were used as a precursor, stabilizer agent, and solvent, respectively. Au and Ag NPs were synthesized by (PLAL) technique using “Q-Switched ND-YAG laser” system with laser parameters (520 mJ laser energy, 1064 nm wavelength, 450 laser pulses, and 1Hz frequency). The volumetric ratios of ZnO source solution to Au and Ag colloidal solutions were 3:2 and 4:1, respectively. The morphological, structural and optical properties of ZnO thin films embedded with Au and Ag NPs were investigated. The patterns of x-ray diffraction (XRD) showed peaks indexed to (100), (002) and (101) planes for ZnO and (111), (200) and (220) for Au and Ag NPs. The surface morphology of the films was examined by FESEM and the Raman spectra of ZnO thin films embedded with Ag and Au NPs were investigated. Furthermore, the optical properties of the films were analyzed by UV-Vis spectroscopy measurements. The optical band gap of the films increased with increasing the volumetric ratios of ZnO embedded with Au and Ag NPs.