Room-temperature NH3 sensing of graphene oxide film and its enhanced response on the laser-textured silicon

Abstract

Electricity-based response to NH₃ of graphene oxide (GO) is demonstrated at ppm level at room temperature. The GO film prepared on planar silicon substrate shows weak response when exposed to 50 ppm NH₃, response time less than 30 s and recovery time about 100 s. More interestingly, the GO film coated on laser-textured silicon substrate shows significant enhancement for sensor response, and meanwhile response/recovery time is mainly preserved. Furthermore, a good response of textured GO film is detected in a dynamic range of 5-100 ppm NH₃. The surface morphology and chemical bonds of the textured GO film are studied by scanning electron microscope (SEM), Fourier Transform Infrared (FT-IR) Spectrometer and X-ray Photoelectron Spectrometer (XPS), respectively. The NH₃ response is attributed to the polar oxygen configurations of GO and the enhanced response is due to the richer oxygen configurations that stem from cobwebby microstructure of GO.