Growth of silver on ZnO and SnO2 thin films intended for low emissivity applications

Abstract

In the present work we have investigated the relationships existing between the optical properties and the growth mechanism, microstructure and surface roughness of SnO 2 and ZnO oxide films prepared by magnetron sputtering under conditions resembling those utilized in industry. Thin films of these oxides with different thicknesses were characterized by atomic force microscopy, glancing incidence X-ray diffraction (GIXRD), X-ray reflectometry and spectroscopic Ellipsometry. The roughness evolution of the film properties (density, surface roughness and refraction index) as a function of their thickness has been evaluated within the concepts of the Dynamic Scaling Theory of thin film growth. Zinc oxide films were rougher than tin oxide films of similar *Manuscript Click here to view linked References 2 thickness, indicating a different growing mechanism for the two materials. Silver was evaporated onto the surface of the two oxide thin films and its earlier stages of nucleation studied by background analysis of the X-ray photoemission spectra. A different nucleation mechanism was found depending on the nature of the oxide acting as substrate. The superior performance of the zinc oxide based low emissive coatings is related with a better wetting of silver on the surface of this oxide despite the comparatively lower roughness of the tin oxide layers.

Spreadability of Ag Layer on Oxides and High Performance of AZO/Ag/AZO Sandwiched Transparent Conductive Film

“…Among them, the substrates are undoubtedly important factors because they are related directly to the interaction of Ag atom with that of the substrate [24] and the nucleation and grain growth behavior of Ag layer [25][26][27][28]. In an earlier report [19], it was found that the spreading of Ag on the surface of ZnO was better than that on SnO 2 due to a better affinity between Ag and ZnO though surface of ZnO was rougher than that of the latter. It brings about a question whether there exists any difference between the spreading of Ag on the surface of ZnO and that on ITO.…”

“…With increasing the thickness of Ag layer, the sheet resistance of the Ag/AZO bilayer reduces and is even lower than that of the Ag/ITO bilayer. The reason may be related to the spreadability [19,24] of the Ag layer on the AZO underlayer. As shown in Figure 3, the Ag layer deposited on the AZO has a better spreadability.…”

“…Because the transparent conductive properties of TMT depended mainly on the metal layer [1,9,[14][15][16], a variety of researches on TMT focused on the metal layer [2,[17][18][19][20][21][22]. Generally, the thickness of metal layer was about 8-14 nm [1] because the too thick metal layer made the light transmittance decrease while the too thin one did not form a continuous layer and made the electrical conductivity decrease dramatically.…”

Analysis of a Hybrid Solar Window for Building Integration

“…Multi-layer glazing separated by air, vacuum, inert gas or transparent insulators such as silicon aerogel [7]reduce thermal losses. Tinted or reflective glazing technologies [8][9][10], low emissivity coatings [10,11] and spectrally selective glazing [10][11][12] regulate the spectral response of the window. Switchable glazing technologies such as electrochromic [13][14][15], thermochromic [15,16] or photochromic glazing and liquid crystals [17] have been developed as part of 'smart' fenestration systems to provide varying levels of daylighting and passive thermal control for the interior.…”

Heterojunction thin films based on multifunctional metal oxides for photovoltaic application

“…ZnO/SnO 2 (ZS) is one of the most important TCO materials. It has numerous applications in modern technologies due to its attractive properties such as wide band gap, high electrical conductivity, high transmittance in the ultraviolet-visible (UV-Vis) region, high infrared (IR) reflectance, and its abundance in nature [3]. Quantum dots (QDs) based semiconducting materials are beneficial due to their unique optical and electrical properties.…”