VO2 Films Decorated with an MXene Interface for Decreased-Power-Triggered Terahertz Modulation

Wang, D and Gao, C and Wang, Y and Chang, X and Hu, Y and Li, J and Feng, T and Dey, JK and Roul, B and Lu, X and Du, L and Zhai, Z and Zhu, H and Huang, W and Das, S and Su, F and Zhu, L-G and Shi, Q (2024) VO2 Films Decorated with an MXene Interface for Decreased-Power-Triggered Terahertz Modulation. In: ACS Applied Materials and Interfaces, 16 (8). pp. 10886-10896.

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Abstract

VO2, which exhibits semiconductor-metal phase transition characteristics occurring on a picosecond time scale, holds great promise for ultrafast terahertz modulation in next-generation communication. However, as of now, there is no reported prototype for an ultrafast device. The temperature effect has been proposed as one of the major obstacles. Consequently, reducing the excitation threshold for the phase transition would be highly significant. The traditional strategy typically involves chemical doping, but this approach often leads to a decrease in phase transition amplitude and a slower transition speed. In this work, we proposed a design featuring a highly conductive MXene interfacial layer between the VO2 film and the substrate. We demonstrate a significant reduction in the phase transition threshold for both temperature and laser-induced phase transition by adjusting the conductivity of the MXene layers with varying thicknesses. Our observations show that the phase transition temperature can be decreased by 9 °C, while the pump fluence for laser excitation can be reduced by as high as 36. The ultrafast phase transition process on a picosecond scale, as revealed by the optical-pump terahertz-probe method, suggests that the MXene layers have minimal impact on the phase transition speed. Moreover, the reduced phase transition threshold can remarkably alleviate the photothermal effect and inhibit temperature rise and diffusion in VO2 triggered by laser. This study offers a blueprint for designing VO2/MXene hybrid films with reduced phase transition thresholds. It holds significant potential for the development of low-power, intelligent optical and electrical devices including, but not limited to, terahertz modulators based on phase transition phenomena. © 2024 American Chemical Society.

Item Type:	Journal Article
Publication:	ACS Applied Materials and Interfaces
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to the American Chemical Society.
Keywords:	Laser excitation; Optical pumping; Probes; Semiconductor lasers; Temperature; Vanadium dioxide, Mxene; Picosecond time scale; Power; Pump probe; Semiconductor-metal phase transition; Tera Hertz; Transition speed; Ultra-fast; Ultrafast devices; VO2 films, Semiconductor doping, article; conductance; controlled study; diffusion; drug development; electric potential; excitation; laser; phase transition; semiconductor; temperature; temperature sensitivity; thickness; transition temperature; velocity
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	10 Apr 2024 05:24
Last Modified:	10 Apr 2024 05:24
URI:	https://eprints.iisc.ac.in/id/eprint/84676

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