Diamond growth by laser-driven reactions in a CO/H2 mixture

Abstract
Diamond growth is observed on diamond‐abraded single crystal Si(111) substrates from a 99.3%H2/0.7%CO gas mixture at a total pressure of 8 Torr. The gas mixture is reacted by using 193 nm irradiation from an ArF excimer laser. Multiphoton dissociation of CO takes place via the a3Π state, with subsequent chemical reactions between C and O fragments and hydrogen. Of importance is the fact that we observe significant diamond particle growth within a period of 1 h on unheated substrates. This research represents the first known effort where diamond growth is observed at room temperature.