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Effect of thermal treatment on the growth, structure and luminescence of nitride-passivated silicon nanoclusters.

Wilson PR, Roschuk T, Dunn K, Normand EN, Chelomentsev E, Zalloum OH, Wojcik J, Mascher P - Nanoscale Res Lett (2011)

Bottom Line: Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effects that deposition and processing parameters have on their growth, luminescent properties, and electronic structure.The emission energy was highly dependent on the film composition and changed only slightly with annealing temperature and time, which primarily affected the emission intensity.The PL spectra from films annealed for duration of times ranging from 2 s to 2 h at 600 and 800°C indicated a fast initial formation and growth of nanoclusters in the first few seconds of annealing followed by a slow, but steady growth as annealing time was further increased.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Engineering Physics and Centre for Emerging Device Technologies, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S4L7, Canada. wilsonpr@mcmaster.ca.

ABSTRACT
Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effects that deposition and processing parameters have on their growth, luminescent properties, and electronic structure. Luminescence was observed from Si-ncs formed in silicon-rich silicon nitride films with a broad range of compositions and grown using three different types of chemical vapour deposition systems. Photoluminescence (PL) experiments revealed broad, tunable emissions with peaks ranging from the near-infrared across the full visible spectrum. The emission energy was highly dependent on the film composition and changed only slightly with annealing temperature and time, which primarily affected the emission intensity. The PL spectra from films annealed for duration of times ranging from 2 s to 2 h at 600 and 800°C indicated a fast initial formation and growth of nanoclusters in the first few seconds of annealing followed by a slow, but steady growth as annealing time was further increased. X-ray absorption near edge structure at the Si K- and L3,2-edges exhibited composition-dependent phase separation and structural re-ordering of the Si-ncs and silicon nitride host matrix under different post-deposition annealing conditions and generally supported the trends observed in the PL spectra.

No MeSH data available.


Related in: MedlinePlus

PL spectra for films with Siex = 3% annealed at 600°C. The annealed spectra are renormalized to have equal peak heights and offset in order of increased annealing time to clearly show the shifting in peak PL energy that occurred with annealing.
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Figure 8: PL spectra for films with Siex = 3% annealed at 600°C. The annealed spectra are renormalized to have equal peak heights and offset in order of increased annealing time to clearly show the shifting in peak PL energy that occurred with annealing.

Mentions: As described previously, in the case of isochronal annealing for 60 min in a quartz tube furnace, the PL of SRSN films with moderate-to-high excess silicon content tends to shift towards lower energies as the annealing temperature increases. Such a shift is in agreement with theory for quantum confinement effects corresponding to the growth of Si-ncs where the bandgap energy is proportional to the inverse square of the nanocluster diameter. Figure 8 shows the PL spectra for a film with 3% excess Si content annealed at 600°C for time intervals ranging from a mere 2 s to 2 h. In this figure, the annealed PL spectra were renormalized to have the same peak height to aid in comparing changes in emission energies while the AD spectra was renormalized to maintain its relative intensity compared to the 2 s anneal. Each spectrum consisted of a main peak that shifted to lower energies as the annealing time increased, and a higher energy shoulder that was most prominent in the AD film, which diminished as the annealing time increased. There was an abrupt red-shift in peak emission energy from 2.58 eV in the AD film to 2.13 eV after only 2 s of annealing along with a large increase in intensity. As the annealing time was increased further, the PL peak continued to shift towards lower energies, but these changes were relatively small compared to the initial shift. This indicates that Si-ncs form and begin to grow very rapidly through a transient diffusion of excess silicon.


Effect of thermal treatment on the growth, structure and luminescence of nitride-passivated silicon nanoclusters.

Wilson PR, Roschuk T, Dunn K, Normand EN, Chelomentsev E, Zalloum OH, Wojcik J, Mascher P - Nanoscale Res Lett (2011)

PL spectra for films with Siex = 3% annealed at 600°C. The annealed spectra are renormalized to have equal peak heights and offset in order of increased annealing time to clearly show the shifting in peak PL energy that occurred with annealing.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211220&req=5

Figure 8: PL spectra for films with Siex = 3% annealed at 600°C. The annealed spectra are renormalized to have equal peak heights and offset in order of increased annealing time to clearly show the shifting in peak PL energy that occurred with annealing.
Mentions: As described previously, in the case of isochronal annealing for 60 min in a quartz tube furnace, the PL of SRSN films with moderate-to-high excess silicon content tends to shift towards lower energies as the annealing temperature increases. Such a shift is in agreement with theory for quantum confinement effects corresponding to the growth of Si-ncs where the bandgap energy is proportional to the inverse square of the nanocluster diameter. Figure 8 shows the PL spectra for a film with 3% excess Si content annealed at 600°C for time intervals ranging from a mere 2 s to 2 h. In this figure, the annealed PL spectra were renormalized to have the same peak height to aid in comparing changes in emission energies while the AD spectra was renormalized to maintain its relative intensity compared to the 2 s anneal. Each spectrum consisted of a main peak that shifted to lower energies as the annealing time increased, and a higher energy shoulder that was most prominent in the AD film, which diminished as the annealing time increased. There was an abrupt red-shift in peak emission energy from 2.58 eV in the AD film to 2.13 eV after only 2 s of annealing along with a large increase in intensity. As the annealing time was increased further, the PL peak continued to shift towards lower energies, but these changes were relatively small compared to the initial shift. This indicates that Si-ncs form and begin to grow very rapidly through a transient diffusion of excess silicon.

Bottom Line: Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effects that deposition and processing parameters have on their growth, luminescent properties, and electronic structure.The emission energy was highly dependent on the film composition and changed only slightly with annealing temperature and time, which primarily affected the emission intensity.The PL spectra from films annealed for duration of times ranging from 2 s to 2 h at 600 and 800°C indicated a fast initial formation and growth of nanoclusters in the first few seconds of annealing followed by a slow, but steady growth as annealing time was further increased.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Engineering Physics and Centre for Emerging Device Technologies, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S4L7, Canada. wilsonpr@mcmaster.ca.

ABSTRACT
Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effects that deposition and processing parameters have on their growth, luminescent properties, and electronic structure. Luminescence was observed from Si-ncs formed in silicon-rich silicon nitride films with a broad range of compositions and grown using three different types of chemical vapour deposition systems. Photoluminescence (PL) experiments revealed broad, tunable emissions with peaks ranging from the near-infrared across the full visible spectrum. The emission energy was highly dependent on the film composition and changed only slightly with annealing temperature and time, which primarily affected the emission intensity. The PL spectra from films annealed for duration of times ranging from 2 s to 2 h at 600 and 800°C indicated a fast initial formation and growth of nanoclusters in the first few seconds of annealing followed by a slow, but steady growth as annealing time was further increased. X-ray absorption near edge structure at the Si K- and L3,2-edges exhibited composition-dependent phase separation and structural re-ordering of the Si-ncs and silicon nitride host matrix under different post-deposition annealing conditions and generally supported the trends observed in the PL spectra.

No MeSH data available.


Related in: MedlinePlus