Origin of visible photoluminescence from porous silicon as studied by Raman spectroscopy

Abstract

In this paper we discuss the different models proposed to explain the visible luminescence in porous silicon (PS). We review our recent photoluminescence and Raman studies on PS as a function of different preparation conditions and isochronal thermal annealing. Our results can be explained by a hybrid model which incorporates both nanostructures for quantum confinement and silicon complexes (such as SiH_x and siloxene) and defects at Si/SiO₂ interfaces as luminescent centres.