Luminescence of free-standing versus matrix-embedded oxide-passivated silicon nanocrystals: The role of matrix-induced strain

Abstract

On the method of photoluminescence spectral intensity ratio imaging of silicon bricks: Advances and limitations J. Appl. Phys. 112, 063116 (2012) Measurement of net dopant concentration via dynamic photoluminescence J. Appl. Phys. 112, 063704 (2012) Luminescence and deep-level transient spectroscopy of grown dislocation-rich Si layers AIP Advances 2, 032152 (2012) The role of excess minority carriers in light induced degradation examined by photoluminescence imaging J. Appl. Phys. 112, 033703 (2012) Effect of hydrofluoric acid concentration on the evolution of photoluminescence characteristics in porous silicon nanowires prepared by Ag-assisted electroless etching method

Structural parameters effect on the electrical and electroluminescence properties of silicon nanocrystals/SiO2 superlattices

“…The optimum conditions when both effects are minimized, namely, a lower presence of free carriers and low enough matrix stress, are reached at t SiO2 = 2 nm. Both hypotheses are plausible in the frame where the NC interaction does not cause a loss of exciton confinement within the NCs (the nanostructure morphology is not varied [33]), which is corroborated by identical Raman spectra (see figure 2(a)) and the constant EL peak position in the spectra shown in figure 4(a). Other competing effects may take place regarding the barrier thickness modification that are related to the NC excitation, which requires a further analysis on the correlation between charge injection within the SLs and the luminescence yielded by the structures, as will be treated in the following section.…”

“…In the opposite case, i.e. for thicker barriers, the higher stress generated by the larger SiO 2 presence surrounding the NCs [11,33] may give rise to an instability of the confined excitons, thus reducing the recombination time. The optimum conditions when both effects are minimized, namely, a lower presence of free carriers and low enough matrix stress, are reached at t SiO2 = 2 nm.…”

Optical emission fromSiO2-embedded silicon nanocrystals: A high-pressure Raman and photoluminescence study

“…Godefroo and co-authors, using PL measurements under high magnetic fields, showed that the optical emission of as-crystallized SiO x /SiO 2 superlattices may be related to defects, whereas it becomes entirely originated by excitonic quantum confinement (QC) after H passivation [7]. Matrix-induced strain has also been shown to play an important role in the optical emission of matrix-embedded Si NCs relative to free-standing material [9].…”

“…In spite of much effort to investigate the optical properties of nanosized Si, the actual origin of its strong PL signal is still under debate [7][8][9][10]. While many experimental works point toward strong luminescence due to quantum-confined excitons in Si nanostructures fabricated with different methods [8,[11][12][13][14], others suggest that the PL emission arises from highly localized surface states [14][15][16][17].…”

Photoluminescence Studies of Li-Doped Si Nanocrystals

“…It has been shown that strain can modify the electronic structure of semiconductor nanocrystals and consequently their PL spectra [15,21,22]. Since we know from our x-ray diffraction measurement that Li-doped SiNCs have an expanded lattice, i.e., tensile strain is present in these nanocrystals, we can expect that the PL spectra will be influenced by this tensile strain.…”