Fabrication and Characterization of an Ultrasensitive Humidity Sensor Based on Chalcogenide Glassy Alloy Thin Films

Surabhi Mishra,1

Priyanka Chaudhary,2

B. C. Yadav,2

Ahmad Umar,3*Email

Pooja Lohia4 

D. K. Dwivedi1*Email

1Amorphous Semiconductor Research Lab, Department of Physics and Material Science, Madan Mohan Malaviya University of Technology, Gorakhpur-273010, India.

2Nanomaterials and Sensors Research Laboratory, Department of Physics, Babasaheb Bhimrao Ambedkar University, Lucknow-226025, Utter Pradesh, India.

3Department of Chemistry, Faculty of Science and Arts and Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, Najran-11001, Kingdom of Saudi Arabia

4Department of Electronics and Communication Engineering, Madan Mohan Malaviya University of Technology, Gorakhpur-273010, India.

Abstract

Herein, a humidity sensor with enhanced sensitivity based on newly prepared chalcogenide glassy alloys thin films was fabricated. Two different chalcogenide glassy alloys, i.e. (Ge11.5Te12.5Se67.5)100 and (Ge11.5Te12.5Se67.5)90Sb10 were prepared, characterized and finally used to fabricate impedance-based humidity sensors at different frequencies. The fabricated humidity sensors based on (Ge11.5Te12.5Se67.5)100 and (Ge11.5Te12.5Se67.5)90Sb10 thin films exhibited high sensitivities of ~8.522 MΩ/%RH and 9.280 MΩ/%RH, respectively. Compared with other humidity sensors based on metal oxides and other nanocomposites, the fabricated humidity sensors based on (Ge11.5Te12.5Se67.5)100 and (Ge11.5Te12.5Se67.5)90Sb10 thin films demonstrated better sensing properties. Moreover, the fabricated sensors revealed faster response and recovery times. The response and recovery times for the fabricated humidity sensor based on (Ge11.5Te12.5Se67.5)100 were 30s and 44s, respectively while the (Ge11.5Te12.5Se67.5)90Sb10 chalcogenide thin film-based humidity sensor shows 28 s response and 34 s recovery times. Based on the perceived results, it can be concluded that the newly prepared chalcogenide glassy alloys thin films based on (Ge11.5Te12.5Se67.5)100 and (Ge11.5Te12.5Se67.5)90Sb10 are promising materials to fabricate high-sensitive humidity sensors for variety of applications.

Fabrication and Characterization of an Ultrasensitive Humidity Sensor Based on Chalcogenide Glassy Alloy Thin Films