Surface reactivity of luminescent porous silicon

Abstract

The effects of addition of a series of organoamine molecules on the luminescence of porous silicon has been examined by steady-state photoluminescence (PL) and Fourier transform infrared spectroscopies. These samples, prepared nonanodically via stain etching techniques and characterized by atomic force microscopy, show dramatic quenching of visible PL upon addition of dilute solutions of the above Lewis base adsorbates. The fractional changes in integrated PL intensity as a function of quencher concentration obey a simple equilibrium model, demonstrating Langmuir-type behavior from which equilibrium constants can be calculated. An observation concomitant with this loss of PL is a diminution of the silicon hydride stretching frequencies near 2100 cm−1.