Laser-induced carbon deposition from supercritical benzene

A catalyst-free deposition of carbon onto a Si substrate immersed into benz ene under supercritical pressure and temperature is induced by radiation of a Cu vapor laser. Raman analysis shows the signal typical of that for glas sy carbon with a broadened D-peak. HRTEM indicates that the carbonaceous sp ecies have the shape of hollow rolls of 3-5 nm in diameter with multilayere d walls with interlayer distance of 0.9 nm. The remaining liquid shows a st rong luminescence in the visible, which is tentatively attributed to format ion of polyaromatic compounds. (C) 2000 Elsevier Science B.V. All rights re served.