Photoluminescence of porous silicon surfaces stabilized through Lewis acidmediated hydrosilylation

Lewis acid mediated hydrosilylation on porous silicon surfaces permits faci le incorporation of a wide variety of functionalities through stable silico n-carbon bonds. The surfaces demonstrate high chemical stability with respe ct to hydrofluoric acid and aqueous base. The effects of the covalently bou nd surface groups on photoluminescence have been investigated and it was no ted that alkyl and alkenyl termination induced only small decreases in phot oluminescence efficiency. Aromatic substituents conjugated through a vinyl group, however, bring about almost complete quenching of the observed photo luminescence, regardless of substitution with either electron withdrawing ( chloride) or donating (methyl) functionalities. The photoluminescence fatig ue of dodecyl terminated surfaces in air for 12-16 h periods has been monit ored and compared to unfunctionalized porous silicon. In air? the photolumi nescence of dodecyl terminated surfaces degrades faster than the unfunction alized porous silicon but under inert atmosphere (nitrogen), the rate of ph otoluminescence fatigue is slow in both cases and approximately equivalent. (C) 1999 Elsevier Science B.V. All rights reserved.