Spatially localized one-dimensional porous silicon photonic crystals

Abstract

The authors report a straightforward method to achieve spatially localized photonic band-gap structures in porous silicon. This photonic band-gap lithography technique consists of local photo-oxidation followed by exposure to methanol solvent. Reflectance measurements show that the oxidized porous silicon regions maintain their photonic band structure with only a slight blueshift while there is significant spectral degradation in the nonoxidized regions. Fourier transform infrared spectroscopy and scanning electron microscopy were performed to investigate this phenomenon. The significant spectral change in the nonoxidized regions is attributed to chemical modification of the porous silicon.