Perovskite-Based Gas Sensing Network for Environmental Condition Monitoring

Abstract

Volatile Organic Compounds (VOCs) are one of the major concerns in terms of environmental pollution. In indoor environment, they can contribute to breathing difficulty, eye irritation, nausea, and can even cause damage to the central nervous system. Detecting the presence of these gases has become essential in environmental monitoring. The aim of this study is to investigate the sensitivity and selectivity of methylammonium lead iodide (MAPbI3) perovskites to an array of different VOC gases under illuminated condition. In our experiment, at first microchannels were created on indium tin oxide (ITO) coated plastic substrates. Then perovskite precursor solution was dropped on the microchannels, and leveraging the capillary motion force, the microchannels were filled eventually. After the crystallization of the solution, the perovskite was exposed to the VOCs and the current-voltage (I-V) characteristic responses of the perovskite before and after the exposure to the gases were studied. The photocurrent response to ethanol, methanol and acetone have been studied, and a variation among them has been observed. The sensor exhibited negligible changes in I-V response to ethanol and acetone, however, upon exposure to methanol, at 2.0 V voltage bias, the photocurrent decreased by about 25%. Our initial study also indicates that the photocurrent response is significantly affected under illuminated condition and one of the major concerns of this study is to investigate how lights of different wavelengths can influence the responsivity of the device. The experimental data for sensing VOCs at room temperature shows great promise for the development of an array of gases sensing devices that can be integrated into an “electronic nose” for detecting the presence of harmful gases in the environment.