Effect of mixing ratio on NO2 gas sensor response with SnO2-decorated carbon nanotube channels fabricated by one-step dielectrophoretic assembly

We fabricated nitrogen dioxide (NO2) gas sensors with p-type carbon nanotubes (CNTs) / n-type tin (SnO2) nanoparticle heterojunctions using one-step dielectrophoretic assembly and investigated the effect of CNT/SnO2 ratio on their NO2 detection properties. CNTs SnO2 nanoparticles were mixed in various ratios, suspended deionized water, assembled by dielectrophoresis. The normalized response heterojunction against 1 ppm was ?80 an N2 atmosphere ?20 artificial air, where UV irradiation used only for initialization. To reduce oxygen (O2), we also conducted continuous intensities during initialization detection. pn sensor had a maximum 19 while that 3. Furthermore, plotting as function concentration reveals detected low 20 ppb air.