Nature of visible luminescence and its excitation in Si–SiO systems

Khomenkova, L.; Korsunska, N.; Yukhimchuk, V. A.; Jumayev, B.; Torchynska, T. V.; Hernandez, A. Vivas; Many, A.; Goldstein, Y.; Savir, E.; Jędrzejewski, J.

doi:10.1016/s0022-2313(02)00628-2

Cited by 51 publications

(51 citation statements)

References 33 publications

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“…The red-range PL shows good agreement between the phase separation/NC formation and the PL peak shift/intensity change, which can be explained by the QCE. Several authors 26,33,34 also described two PL bands in blue-green and yellow-red ranges from SiO x . They attributed the blue-green band to the carrier recombination at defects and the yellowred band to the recombination of confined electron-hole pairs in Si NCs, which is consistent to our results.…”

Section: Red-range Plmentioning

confidence: 98%

Annealing and oxidation of silicon oxide films prepared by plasma-enhanced chemical vapor deposition

Chen

Tang

et al. 2004

Journal of Applied Physics

111

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We have investigated phase separation, silicon nanocrystal (Si NC) formation and optical properties of Si oxide (SiO x , 0Ͻ x Ͻ 2) films by high-vacuum annealing and dry oxidation. The SiO x films were deposited by plasma-enhanced chemical vapor deposition at different nitrous-oxide/silane flow ratios. The physical and optical properties of the SiO x films were studied as a result of high-vacuum annealing and thermal oxidation. X-ray photoelectron spectroscopy (XPS) reveals that the as-deposited films have a random-bonding or continuous-random-network structure with different oxidation states. After annealing at temperatures above 1000°C, the intermediate Si continuum in XPS spectra (referring to the suboxide) split to Si peaks corresponding to SiO 2 and elemental Si. This change indicates the phase separation of the SiO x into more stable SiO 2 and Si clusters. Raman, high-resolution transmission electron microscopy and optical absorption confirmed the phase separation and the formation of Si NCs in the films. The size of Si NCs increases with increasing Si concentration in the films and increasing annealing temperature. Two photoluminescence (PL) bands were observed in the films after annealing. The ultraviolet (UV)-range PL with a peak fixed at 370-380 nm is independent of Si concentration and annealing temperature, which is a characteristic of defect states. Strong PL in red range shows redshifts from ϳ600 to 900 nm with increasing Si concentration and annealing temperature, which supports the quantum confinement model. After oxidation of the high-temperature annealed films, the UV PL was almost quenched while the red PL shows continuous blueshifts with increasing oxidation time. The different oxidation behaviors further relate the UV PL to the defect states and the red PL to the recombination of quantum-confined excitions.

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Section: Red-range Plmentioning

confidence: 98%

Annealing and oxidation of silicon oxide films prepared by plasma-enhanced chemical vapor deposition

Chen

Tang

et al. 2004

Journal of Applied Physics

111

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“…Several authors also described two PL bands in the blue-green and yellow-red ranges from SiO x . [34][35][36] They attributed the blue-green band to the carrier recombination at surface states or defects and the yellow-red band to the recombination of confined electronhole pairs in Si NCs.…”

Section: Optical Absorption and Photoluminescence Of The Depositedmentioning

confidence: 99%

Optical properties of SiOx nanostructured films by pulsed-laser deposition at different substrate temperatures

Chen

et al. 2004

Journal of Applied Physics

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Silicon oxide ͑SiO x ͒ nanostructured films have been formed by pulsed-laser deposition of Si in oxygen at different substrate temperatures, in order to study the structures and optical properties related to quantum confinement effects. After laser ablation, the single-crystal Si(100) target is converted to a polycrystal structure and shows weak photoluminescence (PL). The as-deposited SiO x nanostructured films show large particles (i.e., droplets) on a uniform background film. The droplets with weak PL emission have the same high crystallinity as the Si(100) target. Strong PL is observed from the amorphouslike background films rather than from the crystalline droplets. As substrate temperatures increase from room temperature ͑23°C͒ to 800°C, the PL band continually redshifts from 1.9 to 1.6 eV and the optical band gap decreases from 2.9 to 2.1 eV due to the increased Si concentration in the films. After high-vacuum annealing at 800°C, both the PL and optical absorption are enhanced. The optical band gap also decreases after annealing. Combined with the progressive PL redshifts of the SiO x films with increasing Si concentration by plasma-enhanced chemical vapor deposition, the results support the quantum confinement theory.

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“…This may be a result of lower sensibility for the PL measurement system than the EPR equipment. The $2 eV PL peak has also been observed in high-purity silica glass [24], porous silicon [4], and Si-SiO x systems [25], and assigned to optical transition in the NBOHCs. At high temperature (as high as 800-900 1C), the NBOHCs are stable in structure and show no PL peak shift [15,24].…”

Section: Article In Pressmentioning

confidence: 95%

Light emission from as-prepared and oxidized Si nanowires with diameters of 5–15nm

Zhang

Jin

et al. 2005

Journal of Crystal Growth

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Nature of visible luminescence and its excitation in Si–SiO systems

Cited by 51 publications

References 33 publications

Annealing and oxidation of silicon oxide films prepared by plasma-enhanced chemical vapor deposition

Annealing and oxidation of silicon oxide films prepared by plasma-enhanced chemical vapor deposition

Optical properties of SiOx nanostructured films by pulsed-laser deposition at different substrate temperatures

Light emission from as-prepared and oxidized Si nanowires with diameters of 5–15nm

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