Flexible alternating current electroluminescent ammonia gas sensor

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 gassensing 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 chargetransfer process.