Self-powered, flexible and room temperature operated solution processed hybrid metal halide p-type sensing element for efficient hydrogen detection

Abstract

Hydrogen (H 2 ) is a well-known reduction gas and for safety reasons is very important to be detected. The most common systems employed along its detection are metal oxide-based elements. However, the latter demand complex and expensive manufacturing techniques, while they also need high temperatures or UV light to operate effectively. In this work, we first report a solution processed hybrid mixed halide spin coated perovskite films (CH 3 NH 3 PbI 3−x Cl x ) that have been successfully applied as portable, flexible, self-powered, fast and sensitive hydrogen sensing elements, operating at room temperature. The minimum concentrations of H 2 gas that could be detected was down to 10 ppm. This work provides a new pathway on gases interaction with perovskite materials, poses new questions that must be addressed regarding the sensing mechanisms involved. The utilization of halide perovskite sensing elements demonstrates their potential beyond solar cell applications. OPEN ACCESS RECEIVED

Environment-Induced Reversible Modulation of Optical and Electronic Properties of Lead Halide Perovskites and Possible Applications to Sensor Development: A Review

“…Lead mixed halide perovskite thin films are sensitive also to hydrogen ( ) [ 8 ]. Hydrogen is a reducing gas, and since the is a p-type semiconductor, the adsorption of the molecules causes the lowering of the current.…”

“…Exploiting the reversible interaction of mixed perovskite with molecules, inducing a decrease of current in the film, Gagaoudakis et al [ 8 ] have realized portable, flexible, self-powered, fast and sensitive hydrogen sensing elements, operating at room temperature. Concentrations of gas down to 10 ppm could be detected with a sensitivity depending on the concentration and included in the range from 0.3% at 10 ppm to 5.2% at 100 ppm ( Figure 18 b,c).…”

“…This feature limits the application of these materials for the detection in flammable or explosive atmospheres and the investigation of biomaterials. A further drawback of metal oxide resistive sensors is the typical need for pre-treatments in order to induce the sensing properties and the need for expensive deposition techniques for the realization of the sensing devices [ 8 ].…”

Metal Halide Perovskites for High‐Energy Radiation Detection

“…[15] The main concern regarding MHPs for PV applications right now is their apparently inherent chemical and structural instability under ambient conditions, a topic that is currently attracting increasing attention. [16,17] Looking beyond PVs, MHPs continue to demonstrate the huge potential for application in a wider range of opto/electronics including lasers, [18] light-emitting diodes, [19] photodetectors, [20] sensors, [21][22][23] and particle detectors, [24][25][26][27] to name a few. In the area of sensing applications, MHPs have demonstrated the ability to transduce different environmental stimuli into an optical or electrical signal, which can be seen as an added advantage for applications in the field of sensing.…”

“…Looking beyond PVs, MHPs continue to demonstrate the huge potential for application in a wider range of opto/electronics including lasers, [ 18 ] light‐emitting diodes, [ 19 ] photodetectors, [ 20 ] sensors, [ 21–23 ] and particle detectors, [ 24–27 ] to name a few. In the area of sensing applications, MHPs have demonstrated the ability to transduce different environmental stimuli into an optical or electrical signal, which can be seen as an added advantage for applications in the field of sensing.…”