Flexible alternating current electroluminescent ammonia gas sensor

Abstract

In this work, the fabrication and performance of flexible alternating current electroluminescent (AC-EL) devices for ammonia (NH₃) detection at room temperature are presented for the first time. The AC-EL gas sensor was fabricated by the screen-printing of a ZnS:Cu,Cl phosphor and PEDOT:PSS sensing layers. The effects of parameters including applied voltage, excitation frequency and waveform on light emission and luminance intensity of the AC-EL gas sensor were systematically investigated. From gas-sensing characterization, the AC-EL gas sensor exhibited very high selectivity and a linear response to NH₃ in the concentration range of 100–1000 ppm at room temperature. A sensing mechanism of the EL gas sensor was proposed based on the resistance change of the PEDOT:PSS sensing layer via a charge-transfer process.