Study of the influence of the ZnO:Al polycrystalline film morphology on the silver nanoparticles formation

Abstract

The paper presents the results of the optical and structural properties studies of samples consisting of ZnO:Al (AZO) oxide films with an intermediate silver nanoparticles layer. Obtaining samples were carried out by the method of sol-gel technology using different types of composition, and the conditions for drying and final annealing of the samples were varied. The study of the samples optical properties consisted of the optical absorption spectra measurements, and their structural properties were determined by X-ray diffraction and small-angle X-ray scattering. Comparison of data obtained from measurements of optical and structural properties of samples confirmed the results obtained from modeling in the Comsol Multiphysics software. X-ray diffraction demonstrated that the AZO films have a polycrystalline structure and are highly textured in the [002] direction. Zinc oxide grains are 10-15 nm. Silver nanoparticles are the comparable with AZO grains and have dimensions of several tens of nanometers. An increase in the annealing temperature of the films leads to a redistribution of silver nanoparticles in the AZO film, the distance between the particles increases. Consequently, the effect of the plasmon eigenmodes of the nanoparticles prevails over the effect of the system of particles oscillations interacting with each other. The analysis of the coatings obtained by the method of small-angle X-ray scattering showed that nanoparticles in the AZO film form an ordered structure.

Light Scattering Calculations for Spherical Metallic Nanoparticles (Ag, Au) Coated by TCO (AZO, ITO, PEDOT:PSS) Shell

“…Therefore, the exploitation of LSPR of Ag and Au nanostructures is one of the key approaches to increase the optical absorption, by light trapping, in thin film Si solar cells, organic solar cells, and new-generation solar cells [ 1 , 2 , 3 , 4 , 5 , 13 , 14 ]. So, several schemes for functional devices incorporating plasmonic Ag and Au nanoparticles were recently proposed [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. Generally, this can be achieved by the scattering of light, by the metal nanoparticles, at the cell’s interfaces, either by transmission at the top interfaces or by reflection at the rear ones [ 34 ].…”

“…For specific resulting performances, so, the system needs to be geometrically optimized to maximize scattering and minimize light absorption within the metal nanoparticles across the wavelength range of interest. In solar cell applications, the Ag or Au nanoparticles are usually supported on or embedded in a thin transparent conductive oxide (TCO) layer [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. TCOs are widely used as transparent electrodes for a variety of solar cell devices [ 35 ].…”