Determination of sensoric parameters of porous silicon in sensing of organic vapors

Photoluminescence (PL) properties of as-prepared and surface derivatized porous silicon (PS) in the presence of organic compounds in gas phase were studied. Surface derivatization, aimed at increasing stability of porous silicon properties, was performed by Lewis acid mediated hydrosilylation with methyl 10-undecenoate. We have systematically measured changes in photoluminescence intensity for a set of alcohols from C-1 to C-6. From the variation of the photoluminescence quenching response as a function of alcohol concentration, we determine the sensitivities and detection limits of our porous silicon sensors and these correlate with physical and chemical properties of studied species. For methyl 10-undecenoate derivatized PS samples, we have observed a remarkable enhancement of the selectivity for C-4-C-6 alcohols as compared with C-1-C-3 alcohols. (C) 2002 Elsevier Science B.V. All rights reserved.