Synthesis of Cs2TeI6 thin film and its NO2 gas-sensing properties under blue-light illumination

In this study, a thin film of Cs2TeI6 perovskite with a thickness of 1.27 mm was prepared on a glass substrate via a non-solution process. The characteristics of the material such as phase structure, morphology, optical absorption were studied. The gas-sensing properties of the Cs2TeI6-based sensor were investigated at 25 degrees C using various gases under illumination of a 450-nm laser. Under the blue-light illumination, the sensor exhibited good selectivity toward NO2 gas, with a very low limit of detection of 25 ppb and responsivity of 4.4% toward 1 ppm NO2. The NO2-sensing mechanism was proposed and discussed in term of a surface depletion model. The effects of light intensity, light wavelength, humidity, and long-term duration on NO2-sensing performances were further studied, showing its potential for application into NO2 gas sensors at room temperature. (c) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Automated summary

A thin film of Cs2TeI6 perovskite was prepared on a glass substrate via a non-solution process, and its gas-sensing properties, especially the high selectivity and low detection limit for NO2 gas, were studied. The results show the potential application of this sensor for NO2 gas sensing at room temperature.