Controlled shift in emission wavelength from patterned porous silicon using focused ion beam irradiation

Photoluminescence images containing several distinct color emissions, from green to red, have been obtained using high-energy focused ion beam irradiation, in conjunction with metal-aided anodization of 4 Omega cm p-type silicon. The ion irradiation increases the local resistivity in a controlled manner resulting in smaller hole currents flow through the irradiated areas. This causes a controlled redshift of up to 200 nm in the photoluminescence emission, which in terms of the quantum confinement model would correlate to larger nanocrystallites forming in the irradiated region. (c) 2005 The Electrochemical Society.