Effect of Annealing Time on the Growth, Structure, and Luminescence of Nitride-Passivated Silicon Nanoclusters

Abstract

Rapid thermal annealing has been used to study the changes in luminescence and structure from silicon-rich silicon nitride films for annealing times ranging from 2 seconds to 1 hour at 600 and 800°C. Silicon nanoclusters formed within the silicon nitride host matrix provided the source of the luminescence in the films through quantum confinement effects. Room temperature photoluminescence spectra exhibited a large, abrupt red-shift in emission after only 2 seconds of annealing, indicating early formation and growth of the silicon nanoclusters occurs through a fast transient diffusion mechanism. This initial shift was followed by a slower but steady growth of the nanoclusters as the annealing time was increased further. X-ray absorption near edge structure at the Si K- and L3,2-edges supported the trends observed in the photoluminescence spectra, providing evidence of silicon nanocluster growth and restructuring of the silicon nitride host matrix over the course of annealing.

Silicon 1s near edge X-ray absorption fine structure spectroscopy of functionalized silicon nanocrystals

“…16,17,26 However, this "rabbit ear" splitting has not yet been reported in the silicon 1s NEXAFS spectra of nanocrystalline silicon materials (Si-NCs). Silicon 1s NEXAFS spectra of polydisperse 22,23,29 Si-NCs (formed by annealing of silicon rich SiO2 / Si3N4 thin films) as well as Si-NCs with narrow size distributions have been examined, 18,19 but in experiments with inadequate energy resolution to observe this splitting. In this work, the silicon 1s NEXAFS spectroscopy of Si-NCs are examined with an experimental energy resolution similar to the silicon 1s core-hole broadening (ca.…”