Ozone Sensitive Properties of Thin Films of Nanocrystalline Silicon Carbide

Authors A.V. Semenov, D.V. Lubov, M.V. Makhonin

National Technical University «Kharkiv Polytechnic Institute», 2, Kyrpychov St., 61002 Kharkiv, Ukraine

Е-mail savladi@ukr.net
Issue Volume 12, Year 2020, Number 5
Dates Received 1 July 2020; revised manuscript received 15 October 2020; published online 25 October 2020
Citation A.V. Semenov, D.V. Lubov, M.V. Makhonin, J. Nano- Electron. Phys. 12 No 5, 05016 (2020)
DOI https://doi.org/10.21272/jnep.12(5).05016
PACS Number(s) 73.63. – Bd, 07.07.Df
Keywords Ozone sensors, Silicon carbide (9) , Nanocrystalline film, Electrical resistance, Temperature ozone sensitivity. .

In this paper, we investigated the ability of nanocrystalline SiC films to detect ozone in an air mixture under atmospheric pressure for ozone concentrations of 0.1 mg/m3 (maximum allowable concentration) and 4.0 mg/m3. The ozone sensitivity coefficient S (О3) was estimated by the formula S (О3)  (Rg – Ra)/Ra, where Rg and Ra are respectively the film resistances in the presence and absence of ozone in the air atmosphere. The volume flow rate of the ozone-air mixture was 2 l/min. The temperature dependence of the ozone sensitivity coefficient S (O3) was studied in the temperature range 100-450 C. It was found that the maximum values of S (O3) + 0.71 and – 0.80 were observed at temperatures of 280 C and 330 C, respectively, for both concentrations of ozone. Moreover, S (O3) had a positive sign for a temperature of 280 C and a negative value for 330 C. The different polarity of the change in the film resistance at given temperatures was due to the different ratio of redox reactions of ozone with atmospheric gases on the surface of nc-SiC films. Both temperatures can be used for detecting ozone with sensors on nc-SiC films, however, from the point of view of reducing energy consumption, operating temperature of 280 С looks more preferable.

List of References