Low temperature Raman and photoluminescence study of Si/CaF2 multiquantum wells

Papadimitriou, D; Nassiopoulou, AG; Bassani, F; d'Avitaya, FA

dc.contributor.author	Papadimitriou, D	en
dc.contributor.author	Nassiopoulou, AG	en
dc.contributor.author	Bassani, F	en
dc.contributor.author	d'Avitaya, FA	en
dc.date.accessioned	2014-03-01T01:15:40Z
dc.date.available	2014-03-01T01:15:40Z
dc.date.issued	2000	en
dc.identifier.issn	0921-5107	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/13664
dc.subject	nc-Si/CaF2 multiquantum wells photoluminescence	en
dc.subject	Raman	en
dc.subject.classification	Materials Science, Multidisciplinary	en
dc.subject.classification	Physics, Condensed Matter	en
dc.subject.other	CAF2/SI(111) INTERFACE	en
dc.subject.other	GROWTH	en
dc.title	Low temperature Raman and photoluminescence study of Si/CaF2 multiquantum wells	en
heal.type	journalArticle	en
heal.identifier.primary	10.1016/S0921-5107(99)00321-9	en
heal.identifier.secondary	http://dx.doi.org/10.1016/S0921-5107(99)00321-9	en
heal.language	English	en
heal.publicationDate	2000	en
heal.abstract	Raman and photoluminescence (PL) spectroscopy in the temperature range 20-300 K were used to investigate the structural and optical properties of Si/CaF2 multiquantum wells (MQW). The quantum wells were grown by molecular beam epitaxy at room temperature on (111) silicon substrates. Raman spectra were broadened, asymmetric and shifted to lower frequencies compared to those of bulk Si confirming the low dimensionality of the structures. The peak width (FWHM) was that expected for nanocrystallites of dimensions comparable to layer thickness. It increased after cooling to 20 K indicating changes in correlation length. The peak position was shifted to higher frequencies with decreasing temperature following the temperature dependence of bulk silicon. PL spectra consisted of two bands, centered at 530 and 740 nm, respectively. PL-excitation was more effective by irradiation with shorter laser wavelengths. in the range of 400-500 nm. PL emission in the red was temperature dependent. Its intensity increased with decreasing temperature by almost one order of magnitude, while its position was shifted towards shorter wavelengths. The above Raman and PL behavior suggest that carrier localization in silicon nanocrystallites takes place, which is more effective at low temperatures, while at higher temperatures the carriers are weakly delocalized in the nanocrystalline silicon layer. (C) 2000 Elsevier Science S.A. All rights reserved.	en
heal.publisher	ELSEVIER SCIENCE SA	en
heal.journalName	MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY	en
dc.identifier.doi	10.1016/S0921-5107(99)00321-9	en
dc.identifier.isi	ISI:000085591900103	en
dc.identifier.volume	69	en
dc.identifier.spage	546	en
dc.identifier.epage	548	en