Laser-induced carbon deposition from supercritical benzene

A catalyst-free deposition of carbon onto a Si substrate immersed into benzene under supercritical pressure and temperature is induced by radiation of a Cu vapor laser. Raman analysis shows the signal typical of that for glassy carbon with a broadened D-peak. HRTEM indicates that the carbonaceous species have the shape of hollow rolls of 3–5 nm in diameter with multilayered walls with interlayer distance of 0.9 nm. The remaining liquid shows a strong luminescence in the visible, which is tentatively attributed to formation of polyaromatic compounds.