Highly sensitive and selective NO2 chemical sensors based on Al doped NiO thin films. (15th August 2020)

• Record Type: Journal Article
• Authors: Kampitakis, V.; Gagaoudakis, E.; Zappa, D.; Comini, E.; Aperathitis, E.; Kostopoulos, A.; Kiriakidis, G.; Binas, V.
• Is Part Of: Materials science in semiconductor processing. Volume 115(2020)
• Publication Date: 2020-08-15
• Subjects: Nickel oxide -- p-type semiconductors -- RF sputtering -- Thin films -- NO2 -- Gas sensing; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2020.105149
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: Al-doped Nickel oxide (Al:NiO) nanostructured thin films, prepared by RF sputtering technique, were tested for NO2 gas detection. The films were deposited on alumina substrates with thicknesses ranging between 52 nm and 167 nm, while the at.% of Al was varied from 5.0% to 6.7%. The effect of the thickness on the morphological, structural and optical properties was investigated. Moreover, the sensing characteristics were examined and optimized with respect to film thickness and operating temperature (200 °C and 300 °C), at NO2 concentrations ranging from 200 ppb to 2500 ppb and in presence of a constant relative humidity (RH) of 40%. An ultimate response of 271% towards a NO2 concentration of 200 ppb at 200 °C was obtained, concluding that Al:NiO can be potentially used as a sensing material for this specific gas. Highlights: Highly transparent Al-doped NiO films were grown by rf-sputtering technique at RT followed by post-deposition annealing. Al atoms were introduced in the NiO structure and increase significantly the conductivity. Al-doped NiO films appeared to have high response of 271% in 200 ppb NO2, at an operation temperature of 200 °C.