Fabrication and Characterization of an Ammonia Gas Sensor Based on PEDOT-PSS With N-Doped Graphene Quantum Dots Dopant

This paper investigated a room temperature resistive ammonia gas sensor based on a conductive polymer and N-doped graphene quantum dots (N-GQDs) dopant made on a transparent substrate with electrodes. The sensor fabricated with conductive polymer showed a good sensing response that increases considerably with the addition of N-GQDs. The sensing response of the poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) to NH3 increased from 30.13% to 212.32% at 1500 ppm with the addition of 50 wt% N-GQDs. The response time of the N-GQDs doped sensor decreased to 6.8 min when compared with the sensor without N-GQDs and the stability of the sensor having combined N-GQDs and PEDOT-PSS was higher than that of the PEDOT-PSS sensor. Meanwhile, the structure and morphology of the sensing film are characterized by Fourier transform infrared spectroscopy and field emissions scanning electron microscopy.