Photoluminescence of Anodically Oxidized Porous Silicon

Abstract

Abstract A photoluminescence (PL) study is carried out on porous silicon (PS) layers of 50 to 60% porosity which are anodically oxidized in ethylenglycol NH 4 NO 3 electrolyte. Such oxidation is found to make the PL intensity stronger and the peak wavelength shorter. The emission of partially linearly polarized light is observed for PS samples under linearly polarized light excitation. Transmission IR and reflectance spectra are recorded to characterize porous silicon. As a result, a strong shift of the absorption band edge and high silicon oxide content are found in PS sampl. This shift is supposed to be due to the quantum confinement mechanism, but the features of PL speak in favour of the important role of oxide in the light emission from PS. In particular, the polarization of the emitted light can be due to the oxide‐induced elastic strains.