Experimental study of emission properties of carbon nanotubes

This paper describes a new approach to study the emission properties of carbon nanotubes in low distances between two electrodes. Each electrode consists of high doped silicon substrate. The field emission works on the principle that the field emission current is correlated with the electrical field intensity, i.e. the anode-emitter distance when the applied voltage is fixed. This means that the CNTs array serves as the emitter source of electrons between the cathode and the anode in the electric field. The measurement of emission current density flowing through the electrodes is carried out in a vacuum iron-glass vessel pumped by a turbomolecular pump and equipped with feedthroughs for voltage application and current measurement. The vacuum vessel is equipped with a new vacuum compatible linear nano-motion drive SmarAct that enables precise changes of the distance between two electrodes inside the vacuum chamber (step width from 50 nm to 1000 nm, sub-nanometer resolution). Special software, enabling to set up the step size, number of the steps and speed of the motion, is developed for its control. Additionally, a measurement control unit and the software are prepared for an automatic electrical measurement. For this experiment, carbon nanotubes (CNTs) are deposited using a microwave (mw) torch at atmospheric pressure or using a thermal chemical vapour deposition.