Electron field emission from polymer films treated by a pulsed ultravioletlaser

The poly(phenylcarbyne) polymer films were coated on silicon substrates and then irradiated by a pulsed ultraviolet laser (lambda =248 nm) with variou s fluences (1-60 mJ/cm(2)) at an atmospheric pressure of nitrogen. The stru ctures of the resulted films were investigated by Raman spectroscopy. The m orphologies of the films were examined by scanning electron microscopy (SEM ). The electron field emission properties of the films as cathodes were stu died. Raman spectrum analysis and SEM results indicate that the polymer fil m is converted to nanoparticle carbon film with the laser fluence from 10 t o 60 mJ/cm(2). The conversion mechanism from the polymer to nanoparticle ca rbon and electron field emission mechanism from the converted carbon film i s discussed. The converted carbon film showed better field emission propert ies, i.e., lower turn-on threshold emission field, higher emission current density, and higher emission light spot density with increasing laser fluen ce from 10 to 50 mJ/cm(2). By increasing the laser fluence from 50 to 60 mJ /cm(2), the emission property showed a slight degradation. A turn-on thresh old emission field of 1.8 V/mum (at 1 nA/cm(2)) and emission current densit y of 30 mA/cm(2) with an emission light spot density of 10(4)/cm(2) (at 14 V/mum) were observed for the polymer film irradiated with a fluence of 50 m J/cm(2). Circular and multiple-line field emission patterns are demonstrate d using the laser irradiation of the poly(phenylcarbyne) polymer. (C) 2001 American Institute of Physics.