THE PHOTOLUMINESCENCE MECHANISM STUDY IN SILICON NANOCRYSTALS: A QUANTUM CONFINEMENT EFFECT (QCE) MODEL INVESTIGATION

Abstract

Studies on the photoluminescence (PL) emission intensity from many of the silicon-based nanostructured systems has attracted extensive interest to identify its mechanism, in particular, in nanocrystallineSilicon (nc-Si). Despite many recent successes in the field of silicon nanostructures, until now, the origin and properties of the PL are not completely understood. Currently, the underlying mechanisms behind the PL are a major source of debate and dispute among scientist communities. The present paper successfully describes the PL mechanism of nanostructured systems from the Quantum Confinement Effect (QCE) model approach. The selected model (QCE model) assigns the PL to quantum size effects in nc-Si core of the nanostructures. It is widely investigated that one of the fundamental parameters describing the PL mechanisms of nc-Si is the radiative recombination rate. The present investigation revealed that the rate of radiative recombination depends on the diameter d of the spherical nano-crystallites; in particular, the finding clearly confirmed that the radiative recombination rate increases with the decrease in the size of the nc-Si. Certainly, these findings from the QCE model are useful to enhance the PL intensity in nc-Si and possibly useful to tune the PL emission intensity into the visible range.