scholarly journals Fabrication of Transparent Mg(OH)2 Thin Films by Drop-Dry Deposition

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 724
Author(s):  
Tong Li ◽  
Masaya Ichimura

Magnesium hydroxide (Mg(OH)2) thin films were deposited by the drop-dry deposition (DDD) method using an aqueous solution containing Mg(NO3)2 and NaOH. DDD was performed by dropping the solution on a substrate, heating-drying, and rinsing in water. Effects of different deposition conditions on the surface morphology and optical properties of Mg(OH)2 thin films were researched. Films with a thickness of 1−2 μm were successfully deposited, and the Raman peaks of Mg(OH)2 were observed for them. Their transmittance in the visible range was 95% or more, and the bandgap was about 5.8 eV. It was found that the thin films have resistivity of the order of 105 Ωcm. Thus, the transparent and semiconducting Mg(OH)2 thin films were successfully prepared by DDD.

Coatings ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 248 ◽  
Author(s):  
Benjamin Schumm ◽  
Thomas Abendroth ◽  
Saleh A. Alajlan ◽  
Ahmed M. Almogbel ◽  
Holger Althues ◽  
...  

Multilayered nanocoatings allow outstanding properties with broad potential for glazing applications. Here, we report on the development of a multilayer nanocoating for zinc oxide (ZnO) and antimony doped tin oxide (ATO). The combination of ZnO and ATO thin films with their promising optical properties is a cost-efficient alternative for the production of energy-efficient glazing. It is an effective modification of the building envelope to reduce current high domestic demand of electrical power for air conditioning, especially in hot climates like Saudi Arabia. In this paper, we report the development of a nanocoating based on the combination of ZnO and ATO. Principle material and film investigations were carried out on lab-scale by dip coating with chemical solution deposition (CSD), while with regard to production processes, chemical vapor deposition (CVD) processes were evaluated in a second stage of the film development. It was found that with both processes, high-quality thin films and multilayer coatings with outstanding optical properties can be prepared. While keeping the optical transmission in the visible range at around 80%, only 10% of the NIR (near infrared) and below 1% of UV (ultraviolet) light passes these coatings. However, in contrast to CSD, the CVD process allows a free combination of the multilayer film sequence, which is of high relevance for production processes. Furthermore, it can be potentially integrated in float glass production lines.


2021 ◽  
Vol 16 (2) ◽  
pp. 243-248
Author(s):  
Fatmah S. Bahabri ◽  
Alaa Y. Mahmoud ◽  
Wafa A. Alghameeti

In this work, we study the optical properties of the Nickel doped cupric oxide Ni-CuO thin films with Ni various doping concentrations (0, 20, 30, 50, 70, and 80%), at two different annealing temperatures; 200 and 400 °C. The absorbance and optical bandgap for the films are calculated and compared. We find that all films exhibit clear peaks in the visible range, with the increase in the absorptivity via increasing both annealing and Ni concentration. We also find that the annealing affects the shape of the absorbance peaks to be narrowed and blue shifted. Investigation on the direct bandgap energy shows that all films exhibit large direct gap; ranging from 3.87 to 4.01 eV. For non-annealed films, direct bandgap increases with increasing the Ni concentration, while for the annealed samples, the direct bandgap generally decreases by annealing, and with increasing the doping concentration. For the indirect bandgap analysis, the calculated values of the bandgap are ranging from 0.62 to 1.96 eV. We find that for non-annealed films, the indirect bandgap increases with increasing the doping concentration, while after annealing, the bandgap decreases with increasing the doping concentration for the annealing at 200 and 400 °C, with more decreasing in the gap at 400 °C.


2020 ◽  
Vol 27 (09) ◽  
pp. 1950203
Author(s):  
ALI AKHAVAN MAVARDIANI ◽  
MOHAMMAD BAGHER RAHMANI

In this experimental research, tungsten trioxide (WO3) thin films were deposited using ammonium tungstate ((NH4)2WO4) by a simple and cost-effective technique of spray pyrolysis on top of glass substrates. The surface morphology, structural and optical properties of prepared samples were studied using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) pattern analysis and UV–Vis spectroscopy techniques, respectively. Studied deposition parameters were: substrate temperature (300, 350, 400, 450 and 500∘C), concentration of the precursor solution (0.01, 0.02, 0.04, 0.08, 0.1 and 0.2[Formula: see text]M), volume of the precursor solution (50, 100, 150 and 200[Formula: see text]mL) and the effect of pulsed spraying at different concentrations (0.01, 0.1 and 0.2[Formula: see text]M). FESEM images showed that the surface morphology has formed like nested micro-fibrous rings with a uniform distribution all over the surface. The XRD patterns revealed that increasing the solution concentration to 0.2[Formula: see text]M shows some peaks which can be attributed to WO3 with the hexagonal crystal structure. Transmission spectra of the samples indicate that all of the prepared samples are transparent in the visible range, with the calculated direct bandgap ranging from about 2.93[Formula: see text]eV to 3.96[Formula: see text]eV, depending on the deposition conditions.


Coatings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 22 ◽  
Author(s):  
Hanan A. Abd El-Fattah ◽  
Iman S. El-Mahallawi ◽  
Mostafa H. Shazly ◽  
Waleed A. Khalifa

TiN and TiNxOy thin films share many properties such as electrical and optical properties. In this work, a comparison is conducted between TiN (with and without annealing at 400 °C in air and vacuum) and TiNxOy thin films deposited by using RF magnetron sputtering with the same pure titanium target, Argon (Ar) flow rate, nitrogen flow rates, and deposition time on stainless steel substrates. In the case of TiNxOy thin film, oxygen was pumped in addition. The optical properties of the thin films were characterized by spectrophotometer, and Fourier transform infrared spectroscopy (FTIR). The morphology, topography, and structure were studied by scanning electron microscope (SEM), atomic force microscope (AFM), and X-ray diffraction (XRD). The results show that both thin films have metal-like behavior with some similarities in phases, structure, and microstructure and differences in optical absorbance. It is shown that the absorbance of TiN (after vacuum-annealing) and TiNxOy have close absorbance percentages at the visible range of light with an unstable profile, while after air-annealing the optical absorbance of TiN exceeds that of TiNxOy. This work introduces annealed TiN thin films as a candidate solar selective absorber at high-temperature applications alternatively to TiNxOy.


Optik ◽  
2019 ◽  
Vol 199 ◽  
pp. 163517 ◽  
Author(s):  
Mahsa Etminan ◽  
Nooshin. S. Hosseini ◽  
Narges Ajamgard ◽  
Ataalah Koohian ◽  
Mehdi Ranjbar

1989 ◽  
Vol 152 ◽  
Author(s):  
U. J. Gibson

ABSTRACTThe microstructure and optical properties of vacuum evaporated coatings are a sensitive function of the deposition conditions. In recent years, ion bombardment has been used increasingly for the production of denser, more stable coatings of oxides and other materials. In addition to modifying the microstructure, ion bombardment is emerging as a valuable tool for altering the composition (and hence the optical properties) of thin films. A discussion of the effects of ion beam processing and the methods used to analyze the changes in these films is presented.


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