Lead‐Free Cs₂BiAgBr₆ Double Perovskite‐Based Humidity Sensor with Superfast Recovery Time

Abstract

Lead halide perovskites have demonstrated outstanding achievements in photoelectric applications owing to their unique properties. However, the moisture sensitivity of lead halide perovskite has rarely been developed into an applicable humidity sensor due to the intrinsic instability and toxicity issue. Herein, as a highly stable lead-free perovskite, a Cs 2 BiAgBr 6 thin film is chosen to be the active material for humidity sensor due to its extraordinary humidity-dependent electrical properties and good stability. This Cs 2 BiAgBr 6 thin film humidity sensor demonstrates a superfast response time (1.78 s) and recovery time (0.45 s). The superfast response and recovery properties can be attributed to the reversible physisorption of water molecules, which can be easily adsorbed onto or desorbed from the thin film surface. Moreover, the sensor also shows an excellent reliability and stability properties as well as logarithmic linearity in a relative humidity's range of 15% to 78%. The lead-free Cs 2 BiAgBr 6 perovskite possesses great potential for application in real-time humidity sensing.

Recent Developments in Lead‐Free Double Perovskites: Structure, Doping, and Applications

“…Weng et al . used Cs 2 AgBiBr 6 as a humidity sensor, which has operated between 15 % to 78 % relative humidity range.…”

“…Weng et al [20] used Cs 2 AgBiBr 6 as ah umidity sensor, which has operated between 15 %t o7 8% relative humidity range. This humidity sensor was fabricated by recrystallization on Si/SiO 2 substrate.…”

“…Numerous developments have recently happened on double perovskite structure research in terms of different synthesis methods, doping to improve stability, and tuning the emission from the visible to the infrared region . The double perovskite structure has also been applied for humidity sensors, X‐ray detectors, and photocatalysts (dye degradation, CO 2 reduction) and should be discussed comprehensively.…”

“…2020, 15,242 -252 www.chemasianj.org the visible to the infraredr egion. [19] The double perovskite structureh as also been appliedf or humidity sensors, [20] X-ray detectors, [21] and photocatalysts [22] (dye degradation, CO 2 reduction) and should be discussed comprehensively.…”

Printable Highly Stable and Superfast Humidity Sensor Based on Two Dimensional Molybdenum Diselenide

“…Single layer MoSe 2 exhibits an energy band gap of 1.55 eV [36][37][38] . Thus, TMDCs require lesser power for operation than the pervoskites which display a higher energy band gap 39 . MoSe 2 is catalytically active in hydrogen adsorption 30 with 100% Hydrogen interactions at edges, and it has a very low edge binding energy of −13.1 meV/f.u.…”