Analysis of Photoluminiscence in the NCSI-DMA System

Abstract

Silicon nanocrystalline particles (ncSi) were fabricated from the Si swarf using the beads milling method. Observed photoluminiscence spectra (PL) of the ncSi in hexane with the dimethylanthracene molecules (DMA) show photoluminescence peaks at energies of 2.55, 2.75, 2.92, and 3.09 eV. The shape of PL spectra corresponds to the vibronic structure of adsorbed DMA molecules. The PL intensity of the ncSi-DMA system increases by ~3000 times by adsorption of DMA on Si nanoparticles. The PL enhancement results from an increase in absorption probability of incident light by DMA caused by adsorption on the surface of ncSi. Theoretical model of the PL experiment was constructed and resulting model parameters were used in analysis of possible PL transitions and charge transfer processes.