On the effect of laser irradiation and heat treatment on the structure and field-emission properties of carbon nanowalls

Abstract

The composition and structure of carbon nanowalls formed on silicon substrates from the gas phase of hydrogen and methane activated by a direct-current glow discharge are studied by methods of scanning electron microscopy, X-ray diffractometry, IR spectroscopy, and Raman spectroscopy. It is shown that nanowalls are comprised of a porous material consisting of curved lamellar (flaky) crystallites with a thickness of 3–10 nm. The effect of heat treatment and laser irradiation in air on the structure of the carbon nanowalls is studied, and the current–voltage characteristics of field-emission cathodes on their basis are obtained. The heating temperatures and laser-radiation power densities at which the morphology of the surface of carbon nanowalls changes and the characteristics of field-emission cathodes on their basis are determined.