Optical and mechanical characterization of novel cobalt-based metal oxide thin films synthesized using sol–gel dip-coating method

Abstract

ÔØ Å ÒÙ× Ö ÔØOptical and mechanical characterization of novel cobalt-based metal oxide thin films synthesized using sol-gel dip-coating method This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT2 AbstractNew cobalt-based metal oxide thin films (M x Co y O z with M = Mn, Cu, Ni) have been deposited on commercial aluminium and glass substrates using sol-gel dip-coating method.The as-deposited films were characterized by a wide range of complementary techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), Spectrophotometry and Nanoindentation techniques. A light absorption study for coatings on glass substrates within a wavelength range of 300-1100 nm was also conducted. Topographical and morphological investigations showed the presence of nano-sized, grain-like particles in the copper-cobalt oxide coatings, which consequently had the roughest surface among the three coatings. All coatings on glass substrate exhibited higher absorption of ultraviolet (UV) light compared to visible light, while coatings on aluminium substrate generally had low reflectance (< 50 %) of UV light, moderate reflectance (< 80 %) of visible light and high reflectance (up to 100 %) of infrared light. Implications of optical properties as a function of film thickness controlled by dip-heating cycles were discussed. The elastic modulus (E) and hardness (H) of thin film samples compared with standalone commercial aluminium substrate were also measured.

Solar absorptance of copper–cobalt oxide thin film coatings with nano-size, grain-like morphology: Optimization and synchrotron radiation XPS studies

“…Preparation of the cobalt copper oxides thin film coatings was conducted as reported in our previous study [14] Cu/Co molar ratio of 0.5, 1 and 2) were mixed using absolute ethanol. Propionate acid was subsequently added to the solution as a complexing agent and stirred for 2 hours.…”

“…In order to harness the beneficial properties of such metal oxides, we had, therefore, conducted deposition of new cobalt-based metal oxide thin films (M x Co y O z with M = Mn, Cu, Ni) on commercial aluminum and glass substrates using sol-gel dip-coating method [14]. Our study revealed that Cu x Co y O z thin film coatings exhibited favourable optical properties, albeit it was clear that further optimization study would be required to facilitate commercialization of these coatings.…”

Developments in the synthesis of flat plate solar selective absorber materials via sol–gel methods: A review

“…The absorptance of 83.4% (prior to the addition of an antireflection layer) was accomplished using 0.25 M copper acetate and 0.25 M cobalt chloride (Cu/Co ratio=1) with dip-speed 120 mm/min (four cycles). Nanoindentation test using the Berkovich indenter showed that the coatings have a high wear resistance [115][116][117].…”

Tailoring the physicochemical and mechanical properties of optical copper–cobalt oxide thin films through annealing treatment

“…This is quite surprising, in view of the fact that mechanical strength and durability are important in extending their service life. In our previous work, the copper cobalt oxide thin films were deposited on aluminium substrate via the sol-gel dip-coating route [19,20,21]. The resulting coatings exhibited distinctive optical properties with a spectrally selective profile in the UV-Vis-NIR wavelengths region.…”