The fluorinated amorphous carbon nanoparticles (a-C:F NPs) films have been prepared on a porous alumina at a lower temperature of similar to100 degreesC by an ECR-CVD system with a mixture of CF4, C2H2 and Ar as precursors. The morphology of a-C:F NPs films was verified by FESEM. The microstructure and chemical bonding nature of the a-C:F NPs films were investigated by Raman spectroscopy and XPS, respectively. The fluorinated samples need a lower field (similar to2.25 V/mum for 10.6% F a-C:F NPs films) to emit the electron than unfluorinated ones. The excellent field-emission properties of a-C:F NPs films are due to the effect of the shape, fluorine doping and dangling bonds. (C) 2003 Elsevier B.V. All rights reserved.