Abstract
Nowadays, despite the easy fabrication and low cost of metal oxide gas sensors, it is still challenging for them to detect gases at low concentrations. In this study, resistance-matched p-type Cu2O and n-type Ga-doped ZnO, as well as p-type CdO/LaFeO3 and n-type CdO/Sn-doped ZnO sensors were prepared and integrated into p + n sensor arrays to enhance their gas-sensing performance. The materials were characterized by scanning electron microscopy, transmittance electron microscopy, and X-ray diffractometry, and gas-sensing properties were measured using ethanol and acetone as probes. The results showed that compared with individual gas sensors, the response of the sensor array was greatly enhanced and similar to the gas response product of the p- and n-type gas sensors. Specifically, the highly sensitive CdO/LaFeO3 and CdO/Sn-ZnO sensor array had a high response of 21 to 1 ppm ethanol and 14 to 1 ppm acetone, with detection limits of <0.1 ppm. The results show the effect of sensor array integration by matching the two sensor resistances, facilitating the detection of gas at a low concentration.
Highlights
Due to their easy fabrication and low cost, metal oxide (MOX) gas sensors have been widely investigated to be applied in inflammable gas alarms and toxic gas detection [1,2,3,4]
They are extensively used to detect the leakage of inflammable gases such as H2, CH4, etc. in the range of 0.1–5%, their detection of low-concentration gases, such as air pollutants and breath organics at the ppb-ppm level, is still technologically challenging [5,6,7,8,9,10,11]
Chen et al reported that Fe2 O3 /SnO2 core–shell nanorods had a high response of 20 to 10 ppm ethanol [20], and Zhang et al synthesized heterostructured ordered ZnO-Fe3 O4 inverse opal materials for the highly sensitive detection of acetone with a response of 2 to 1 ppm acetone [13]
Summary
Due to their easy fabrication and low cost, metal oxide (MOX) gas sensors have been widely investigated to be applied in inflammable gas alarms and toxic gas detection [1,2,3,4]. Chen et al reported that Fe2 O3 /SnO2 core–shell nanorods had a high response of 20 to 10 ppm ethanol [20], and Zhang et al synthesized heterostructured ordered ZnO-Fe3 O4 inverse opal materials for the highly sensitive detection of acetone with a response of 2 to 1 ppm acetone [13]. There is another strategy to improve the gas response using a sensor array design. The synthesis of highly sensitive p-type materials and the resistance matching of the p- and n-type sensors are found to be the main aspects of sensor array designs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
