IR photoresponsive VO2thin films and electrically assisted transition prepared by single-step chemical vapor deposition

Rajeswaran, B and Tadeo, IJ and Umarji, AM (2020) IR photoresponsive VO2thin films and electrically assisted transition prepared by single-step chemical vapor deposition. In: Journal of Materials Chemistry C, 8 (36). pp. 12543-12550.

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Abstract

Photodetection based on active materials such as VO2is less complex and less expensive. Usually such a detector's performance depends on the properties of active materials like the absorption coefficient, structural morphology and band gap width. Herein, we report the photoresponse of high quality VO2thin films synthesized by a single-step chemical vapor deposition. The phase was identified by X-ray diffraction and confirmed by Raman spectroscopic studies. Morphological studies by atomic force microscopy and scanning electron microscopy revealed uniform well packed grains in the thin films with a surface roughness of 54 ± 0.9 nm. Temperature variableI-Vanalysis of the thin films exhibited a first order transition with changes in resistance of 3 orders of magnitude and a temperature coefficient of resistance of �1.25 K�1at 30 °C. The infrared photodetector fabricated with synthesized VO2thin films showed good photoresponse properties with excellent stability and reproducibility at room temperature giving responsivity, sensitivity, quantum efficiency and detectivity of 7.13 � 10�2mA W�1, 1272.7, 5.71 � 10�3 and 1.06 � 1011Jones respectively after exposing the films to a 1550 nm laser at a power density of 250 mW cm�2and 10 V bias. We also demonstrated a field assisted thermally induced phase transition by out of plane electrical and piezoforce microscopy measurements on the films. © The Royal Society of Chemistry 2020.

Item Type:	Journal Article
Publication:	Journal of Materials Chemistry C
Publisher:	Royal Society of Chemistry
Additional Information:	copyright for this article belongs to Royal Society of Chemistry
Keywords:	Atomic force microscopy; Chemical vapor deposition; Energy gap; Morphology; Photodetectors; Scanning electron microscopy; Spectroscopic analysis; Surface roughness; Temperature, Absorption co-efficient; First order transitions; Infrared photodetector; Orders of magnitude; Piezoforce microscopy; Raman spectroscopic study; Structural morphology; Temperature coefficient of resistance, Thin films
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	10 Nov 2020 10:15
Last Modified:	10 Nov 2020 10:15
URI:	http://eprints.iisc.ac.in/id/eprint/66975

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