Facile and scalable fabrication of chemiresistive sensor array for hydrogen detection based on gold-nanoparticle decorated SWCNT network

We report a facile and scalable process to fabricate chemiresistive hydrogen sensors based on the single-walled carbon nanotube (SWCNT) network decorated with metal nanoparticles (NPs). In order to obtain the statistical and reliable results in the detection, 100 unitary sensing array are fabricated on a single chip at one go. Two device structures were studied; one coated on top of the SWCNT network (SWCNN) and the other sandwiched by Au-NPs (the Au/SWCNT/Au structure). The sensor response of the Au-NP decorated SWCNN was found to be ∼3.6 and 18.5 times superior to that of the Cu- and Sn-NP coated SWCNN, respectively, at room temperature. Sensing response of the sensor was further improved 3 times from 16.1 to 50% by using the sandwiched structure of Au/SWCNN/Au. Based on reproducible electrical responses and statistical understanding, we also found that the enhancement of sensing response is proportional to the increase of the change in resistance by the Au-NP decoration.