Thickness and UV irradiation effects on the gas sensing properties of Te thin films

• Tellurium thin films were prepared by thermal evaporation technique.
• Tellurium thin films showed excellent gas-sensing properties to H2S at room temperature.
• Tellurium showed a remarkably enhanced response to H2S gas under UV irradiation.
• The reason of the enhanced response by UV irradiation was discussed.

In this research, tellurium thin films were investigated for use as hydrogen sulfide gas sensors. To this end, a tellurium thin film has been deposited on Al2O3 substrates by thermal evaporation, and the influence of thickness on the sensitivity of the tellurium thin film for measuring H2S gas is studied. XRD patterns indicate that as the thickness increases, the crystallization improves. Observing the images obtained by SEM, it is seen that the grain size increases as the thickness increases. Studying the effect of thickness on H2S gas measurement, it became obvious that as the thickness increases, the sensitivity decreases and the response and recovery times increase. To improve the response and recovery times of the tellurium thin film for measuring H2S gas, the influence of UV radiation while measuring H2S gas was also investigated. The results indicate that the response and recovery times strongly decrease using UV radiation.

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