Sheth, Kavan and Kondaiah, P and Niranjan, K and Bysakh, Sandip and Srinivas, G and Barshilia, Harish C (2020) Enhanced photothermal conversion in nanometric scale MoOx multilayers with Al2O3 passivation layer. Thin Solid Films, 701. Art No-137947. ISSN 0040-6090

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Abstract

An optically selective stack based on molybdenum oxide nanometric layers (Mo/MoOx/Mo/MoO3/Al2O3) was designed using SCOUT reflectance simulations and fabricated using balanced magnetron sputtering for applications in solar thermal systems. The material properties were experimentally optimised by varying the process parameters namely: target power, gas flow rates, and deposition time. In the stack, the bottommost Mo metal layer is used to improve adhesion, reduce diffusion while acing as an infrared reflector, the MoOx layer of the tandem stack acts as the primary light absorbing layer, and the topmost MoO3 + Al2O3 layers act as antireflection layers. The individual layers of the optical stack exhibited an amorphous structure as confirmed using X-ray diffraction. The existence of lower oxidation states ( + 4, + 5) of molybdenum in the MoOx layer was revealed by X-ray photoelectron spectroscopy. The stack achieved a high absorptance in the solar spectrum region (alpha = 0.969) and a low thermal emissivity in the infrared region (epsilon = 0.15 at 82 degrees C) at optimal process parameters. The oxidation resistance and thermal stability were evaluated by annealing the samples in vacuum up to 500 degrees C.

Item Type:	Article
Subjects:	Engineering Materials
Divisions:	UNSPECIFIED
Depositing User:	Bidhan Chaudhuri
Date Deposited:	05 Feb 2021 11:18
Last Modified:	05 Feb 2021 11:18
URI:	http://cgcri.csircentral.net/id/eprint/4927

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