Low Pressure Gas Sensing Techniques Based on Carbon Nanotube-metal Schottky Contacts

Carbon nanotube （CNT） has unique structure and excellent physical property. It can be used potentially in gas sensing due to gas adsorptions in CNT-metal contact. The CNT-FET and CNT/Au resistance sensors based on the CNT-metal Schottky junction were constructed by the lift-off and dielectrophoretic （DEP） processes. The sensing performances of two devices were tested for hydrogen and nitrogen gases in low pressure range of 10⁻⁷~10⁻⁵ Pa. The currents of CNT-FET and CNT/Au resistance sensors increased 0.05 μA and 0.14 μA, respectively, which exhibit similar hydrogen sensing performance. The research results have explored a new approach of low pressure sensing.