Hygroscopic effects on AuCl₃-doped carbon nanotubes

Hygroscopic effects on AuCl₃-doped single-walled carbon nanotubes (SWCNTs) were investigated. Various concentrations of AuCl₃ solution were dropped on the random network SWCNT transistors, where the doping effect was confirmed by I-V_g characteristics and a blue shift in the Raman G band. The AuCl₃-doped SWCNT transistor was highly sensitive to water vapor in the I-V_g curve, especially in the positive gate bias region, compared with the undoped SWCNT transistors. We also found the selective response of water from ambient gases, such as O₂ and N ₂, in AuCl₃-doped SWCNTs. This investigation could be beneficial for high-performance water sensor applications.