Multimodal Gas Sensor Detecting Hydroxyl Groups with Phase Transition Based on Eco‐Friendly Lead‐Free Metal Halides. (10th April 2022)

• Record Type: Journal Article
• Authors: Lee, Daseul; Lee, Seung‐Jea; Kim, Jae Ho; Park, Juyun; Kang, Yong‐Cheol; Song, Myungkwan; Lee, Hyung Woo; Kim, Han Seul; Choi, Jin Woo
• Is Part Of: Advanced functional materials. Volume 32:Number 28(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-04-10
• Subjects: eco‐friendly -- metal halides -- multimodal gas sensors -- perovskites -- phase transitions; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202202207
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: An electrical and optical responsive chemical‐semiconductor gas sensor is developed using Cu(I) halides with a phase transition mechanism. Cu(I) materials exhibit reversible phase transitions between the Cs3 Cu2 I5 and CsCu2 I3 with different properties, owing to the formation/destruction of the Cs–I and Cu–Cu bonding when the hydroxyl groups are attached/detached. Among various toxic and atmospheric gases, a Cu(I)‐based gas sensor has high selectivity in detecting the hydroxyl group, and the highest sensitivity to water. The reactivity is determined by the polarity, where water with the largest polarity has the strongest attraction for Cu + and I − ions, letting phase transition occur easily. The multimodal sensor red‐shifts emission from 445 to 575 nm when it detects hydroxyl gas, and the moisture‐sensitive sensor visually confirms response to breaths in less than 5 s and recovery in the air in less than 30 s. The gas sensor can operate at room temperature while applying a constant bias voltage of 1 V, and it also shows excellent sensitivity in a relative humidity range of 15–75%. Furthermore, the sensor maintained ≈90% of its initial responsivity over 1 year. Abstract : Based on the chemical reactivity of semiconducting Cs3 Cu2 I5 on a hydroxyl group, phase transition occurs through bond formation and destruction. With this mechanism, a novel electrical and optical multimodal gas sensor is developed based on Cu(I) halide materials. The Cu(I) shows high selectivity and low operation voltage at room temperature.