Gasochromic properties of thin film oxides in terms of surface physics
A novel gasochromism phenomenon is descried using thin films of the ZnO, NiO and WO3 oxide semiconductors under hydrogen exposition, exhibiting rather advantageous properties than previously used fiber optic coating. The oxides were fabricated on glass substrates by RF Magnetron Sputtering technique. Structural and optical characterizations of the semiconductors were completed with XRD, Raman, SEM and optical absorption measurements. To investigate the optical response of these semiconductors to hydrogen gas, an optical gas sensor test system was prepared and programmed during the studies, using charged coupled device (CCD) signal processing. A nano-layer metal sensitizing of Pd and Pt up to 340% on the thin film surfaces of the various oxide samples of ZnO, NiO and WO3 have also been observed in the range of 450-850 nm wave lengths, covering the VIS-IR range. Overall optical response is rather amphoteric for n and p-type materials, having correlation with the resistivity responses. Present applications of the obtained devices on the hydrogen sensing up to low concentrations of 200 ppm, with relatively low response times around 70 s and that of recovery around 200 s, even at the room temperature execution. It is predicted that this extraordinary situation can also be used for various other applications such as smart windows and solar technology, especially in air and oxygen exposure. (c) 2021 Elsevier Ltd. Selection and peer-review under responsibility of the scientific committee of the International Congress on Semiconductor Materials and Devices, ICSMD2018.
- Journal
- MATERIALS TODAY-PROCEEDINGS
- Year
- 2021
- Volume
- 46
- Pages
- 7021-7024
- ISSN
- 2214-7853
- DOI
- 10.1016/j.matpr.2021.03.283
- WoS UID
- WOS:000685932800003