STUDY OF METAL-CNT CONTACT FOR GAS SENSING

Abstract

Two terminal CNT-Metal contact devices are fabricated using different metals (Nickel, Copper and Aluminum). 1-V characteristics of fabricated devices are studied. The barrier height at the CNT-metal contacts is found for these metals using thermionic emission current. Nickel contacts shown the maximum conductance and least barrier height whereas Aluminum contacts shown least conductance and maximum barrier height among the chosen metals. Gases (Carbon Dioxide, Nitrogen and Methane) are used to investigate for gas sensing studies on these devices. The fabricated devices showed a high sensitivity for Carbon dioxide and methane altering the conductance of the devices substantially. They showed very small response time but very large recovery time. Nitrogen adsorbs weakly and thus does not affect the conductance of the devices as other gases.