Absorption Cross Section and Photoluminescence Lifetime of Silicon-Based Light-Emitting nc-Si-SiOx Structures

Abstract

The spectral dependence of the photoluminescence (PL) decay kinetics at room temperature have been studied in porous nc-Si-SiOx nanostructures. Investigated samples were obtained by oblique evaporation of SiO with following annealing at 975 C in vacuum and treating in the HF vapor at 50 C. PL decay in these structures described by a stretched exponential and the average lifetime of the PL decrease exponentially with increasing energy of photons. PL lifetime values is in microsecond range that point out on phonon participation in radiative recombination. Dispersion parameter do not depend on emission energy and tends to 1 with increasing porosity, which is consistent with the model of noninteracting nc-Si. It was established, that the absorption cross section σ of the nc-Si particles increase with decreasing of nc-Si dimensions and increasing of emission energy. This result is consistent with the quantum confinement effects, where the smaller nc-Si with larger energy gaps are characterized by a short radiative lifetime and the corresponding radiative recombination process take place within the individual nc-Si. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/35011