Highly selective sustainable ethanol gas sensor based on p-p heterojunction of SnS/MoSe2 nanocomposite at room temperature

Herein, a high-performance chemiresistive ethanol gas sensor operating at room temperature (RT) is demonstrated based on SnS/MoSe2 nanocomposite. The ethanol-sensing capabilities of the pristine-SnS and SnS/MoSe2 nanocomposite sensor are examined by exposing it to various ethanol concentrations ranging from 50 to 400 ppm at room temperature (RT). The sensing device based on the nanocomposite exhibits a high gas sensing response (Rg/Ra) of 26.8 to 400 ppm for ethanol gas. This results in improved response and recovery times of 9.1 s and 15.7 s respectively, along with high stability, selectivity, and reproducibility. Employing heterojunction in gas-sensing is an effective method for boosting the gas-sensing capabilities of 2D semiconductors. However, selecting semiconductors with compatible energy bands is equally crucial for optimizing gas sensing performance. The synergy arising from the p-p type heterojunction of SnS nanoplates and MoSe2 nanosheets is observed to enhance the sensor's response to ethanol gas. The sensing mechanism of the SnS/MoSe2 nanocomposite sensor is attributed to the formation of p-p heterojunction, modulation of the potential barrier, and charge carrier transfer. The findings suggest that the SnS/MoSe2-based nanocomposite stands out as a potential candidate for fabricating high-performance ethanol gas sensors for electronic applications in environmental monitoring. [Display omitted] •A highly selective room temperature ethanol gas sensor is developed using SnS/MoSe2 nanocomposite.•The sensor shows a high gas sensing response (Rg/Ra) of 26.8 to 400 ppm for ethanol gas.•The sensor demonstrates a rapid response and recovery time of 9.1 s and 15.7 s respectively.•Heterojunction formed between p-type SnS and p-type MoSe2 boosted the sensing performance of the sensor.