A theory for semiconductor nanostructure reactivity to gas environment

A theoretical model has been developed to link the nanostructure geometry o f porous silicon to its optical properties. Light emission and absorption e nergies have been calculated within a variational scheme, which includes a position-dependent boundary condition that reflects the surface chemistry. We show that the results of our measurements of both the photoluminescence (PL) quenching and peak position shift in the presence of oxygen can be acc ounted for by the theory. The model can be considered as a first building b lock of a general theory governing the functioning of semiconductor nanostr ucture-based gas sensors. (C) 2000 Elsevier Science S.A. All rights reserve d.