The Use of Solar Energy for the Production of Fullerenes and Porous Silicon

(Received 6 May 1996, revised and accepted 23 December 1996)

Abstract
We have previously shown that the high intensity of solar radiation, obtained with the Odeillo (France) solar furnace facilities, can be used to vaporize graphite in inert gas atmosphere and to produce fullerenes. After a short survey of the vaporization-condensation method used here, we discuss some of the mechanisms of formation of these molecules and the possibility of increasing the yield, which currently reaches 20%. This technique which presents substantial advantages (use of powders, small rate of UV radiation, possibility of varying pressure and evaporation rate) allow a better knowledge of the mechanisms of formation of fullerene and can be easily used for other material than carbon. As an example, we give first results of production of one porous silicon species exhibiting a strong photoluminescent effect.