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Wavelength-tunable blue photoluminescence of <2 nm Si nanocrystal synthesized by ultra-low-flow-density PECVD / Chung-Hsiang Chang in Acta materialia, Vol. 58 N° 4 (Fevrier 2010) 

Public ISBD [article]  in Acta materialia > Vol. 58 N° 4 (Fevrier 2010) . - pp. 1270–1275 Titre : Wavelength-tunable blue photoluminescence of <2 nm Si nanocrystal synthesized by ultra-low-flow-density PECVD Type de document : texte imprimé Auteurs : Chung-Hsiang Chang, Auteur ; Yi-Hao Pai, Auteur ; Jr-Hau He, Auteur Année de publication : 2011 Article en page(s) : pp. 1270–1275 Note générale : Métallurgie Langues : Anglais (eng) Mots-clés : Photoluminescence  Si  nanocrystal  PECVD  HRTEM Résumé : Strong blue photoluminescence (PL) spectra from Si nanocrystals (Si-ncs) embedded in Si-rich SiOx grown by PECVD at ultra-low N2O flow density and N2O/SiH4 flow ratios are characterized. The N2O flow density is kept as low as 25 sccm to restrict oxygen desorption and to completely facilitate SiH4 decomposition, thus minimizing the oxygen adsorption and suppressing the hydrogen-passivation on dangling bonds at the Si-nc surface. In contrast to the as-grown SiOx, the blue-shifted PL of the annealed SiOx is attributed to the small-size Si-ncs rather than to oxygen vacancy defects. High-resolution transmission electron microscopy analysis reveals dense Si-ncs with diameters of 1.7 ± 0.2 nm in annealed SiOx, contributing to a minimum PL wavelength of 370 nm. X-ray photoelectron spectroscopy indicates a critical O/Si composition ratio of >1.44 for precipitating small Si-ncs with significant Si–Si binding energy peak at 99.0 eV. The weakened hydrogen-passivation effect for precisely manipulating the Si-nc size blue PL is confirmed by Fourier transform infrared spectroscopy. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409007253 [article] Wavelength-tunable blue photoluminescence of <2 nm Si nanocrystal synthesized by ultra-low-flow-density PECVD [texte imprimé] / Chung-Hsiang Chang, Auteur ; Yi-Hao Pai, Auteur ; Jr-Hau He, Auteur . - 2011 . - pp. 1270–1275. Métallurgie Langues : Anglais (eng) in Acta materialia > Vol. 58 N° 4 (Fevrier 2010) . - pp. 1270–1275 Mots-clés : Photoluminescence  Si  nanocrystal  PECVD  HRTEM Résumé : Strong blue photoluminescence (PL) spectra from Si nanocrystals (Si-ncs) embedded in Si-rich SiOx grown by PECVD at ultra-low N2O flow density and N2O/SiH4 flow ratios are characterized. The N2O flow density is kept as low as 25 sccm to restrict oxygen desorption and to completely facilitate SiH4 decomposition, thus minimizing the oxygen adsorption and suppressing the hydrogen-passivation on dangling bonds at the Si-nc surface. In contrast to the as-grown SiOx, the blue-shifted PL of the annealed SiOx is attributed to the small-size Si-ncs rather than to oxygen vacancy defects. High-resolution transmission electron microscopy analysis reveals dense Si-ncs with diameters of 1.7 ± 0.2 nm in annealed SiOx, contributing to a minimum PL wavelength of 370 nm. X-ray photoelectron spectroscopy indicates a critical O/Si composition ratio of >1.44 for precipitating small Si-ncs with significant Si–Si binding energy peak at 99.0 eV. The weakened hydrogen-passivation effect for precisely manipulating the Si-nc size blue PL is confirmed by Fourier transform infrared spectroscopy. DEWEY : 669 ISSN : 1359-6454 En ligne : http://www.sciencedirect.com/science/article/pii/S1359645409007253