Enhanced memristor-based gas sensor for fast detection using a porous carbon nanotube top electrode with membrane

The detection speed of a memristor-based gas sensor (gasistor) is limited because it detects gas passing through the top electrode (TE). In this work, to enhance the response characteristics to nitric oxide (NO) for a hafnium dioxide (HfO2)-based gasistor, we propose the use of a porous carbon nanotube (CNT) electrode and N-[3-(trimethoxysilyl)propyl]ethylenediamine (en-APTAS) familiar with NO. First, the CNT as a TE provides approximately five times more sensitivity to 50-ppm NO than that with the conventional metal-TE. Also, when employing the en-APTAS of 1.5 wt % to further enhance the response/response time to NO, we observe a 2-fold higher response under 50-ppm NO at room temperature (RT), as well as a 134-s faster response time with en-APTAS due to the increased adsorption energy of the electrode. These results indicate that the use of both porous TE and an en-APTAS membrane with high adsorption energies can effectively improve the NO-sensing characteristics of the gasistor.