Low temperature operated ZTO thin film transistor based gas sensor for selective detection of H2S. (1st November 2022)

• Record Type: Journal Article
• Authors: Shaji, Manu; Saji, K.J.; Jayaraj, M.K.
• Is Part Of: Materials science in semiconductor processing. Volume 150(2022)
• Publication Date: 2022-11-01
• Subjects: Amorphous metal oxide -- Zinc tin oxide -- Gas sensor -- Thin film transistor; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2022.106927
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: Amorphous zinc tin oxide bottom gated thin film transistor based H2 S sensor is reported here. On exposure to H2 S, the transfer curve of the device showed a negative directional shift indicating the analyte gas is reducing in nature. A shift of ∼ 6 V was observed in threshold voltage by exposing to 50 ppm H2 S for 120 s compared to the non-exposed device. The fabricated device showed a considerable response value of 0.35 with exposure to 1 ppm H2 S at a lower operating temperature of 70 °C. On exposure to other reducing gases like propanol, ammonia, ethanol, and acetone with a concentration of 50 ppm the transfer curve showed negligible shift, indicating a poor response. The sensor response and recovery time for 1 ppm H2 S exposure were found to be 96 and 123 s, respectively. The sensing mechanism and reason for the large response time were discussed. Selectivity in a mixture of gases was tested, and the device showed a response only to H2 S at lower concentrations. The theoretical limit of detection is calculated to be 150 ppb.