Photon-Enhanced Surface Dissociation Effects in Laser Photolysis of Amorphous Carbon from CH2I2

Abstract

With near-UV Ar+-laser-induced photolysis of gaseous CH2I2, efficient, large-area or localized deposition of iodine-free amorphous carbon is possible at room temperature. The method allows a separate substrate heating and thereby a tuning of the deposits properties from soft and polymer-like to diamond-like. This article reports on an observed photon–surface interaction resulting in an enhanced carbon film formation. The shape of the deposit indicates that the deposition process is supported by an increased absorption cross section of surface-adsorbed intermediate molecular fragments, with respect to flat-angle surface-impinging photons.