Chemical modification of carbon nanotube for improvement of field emission property

In the present work, chemical modification of carbon nanotube was proposed for improvement of field emission property. Multi-wall carbon nanotubes (MWCNTs) were grown vertically on silicon substrate using catalytic chemical vapor deposition. Tips of grown MWCNTs were chemically modified using oxygen plasma, nitric acid, and hydrofluoric acid. Surface state and morphology of the chemically modified CNTs were investigated. CNT tips were opened and defects working as trap sites were generated on the CNT surface by the chemical modification process leading to improvement of field emission property. We suggest that two main factors determining the field enhancement factor are geometric factor and surface state of the CNT tips.