Photoluminescence of silicon nanocrystals embedded in silicon oxidel

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Detail(s)

Original languageEnglish
Pages (from-to)1272-1276
Journal / PublicationJournal of Nanoscience and Nanotechnology
Volume9
Issue number2
Publication statusPublished - Feb 2009

Abstract

The bonding structure and the optical properties of silicon-rich silicon oxide films which were prepared using plasma-enhanced chemical vapor deposition (PECVD) with thermal oxidation were studied in detail. The composition and bonding structures were explored using X-ray photoelectron spectroscopy (XPS). The luminescent properties were studied using Raman spectroscopy and photoluminescence (PL) measurements. Results show that high-temperature ('-'1 000 °C) annealing of as-deposited Si-rich silicon oxide gives rise to phase separation and formation of crystalline Si phases in the oxide films. Upon high temperature annealing, the PL (550-900 nm) intensity was significantly reduced in stoichiometric oxide or in low Si-content (prepared with [N20]/[SiH4j gas flow ratio > 2.5) films whereas an opposite trend was found in higher Si-rich samples. Particularly, for the red band (650 nm) and the infrared band (750 nm), the PL intensity was significantly enhanced by annealing slightly Si-rich samples ([N20]/[SiH4] = 2.5) at 1100 C. This observation was explained by the formation of Si nanocrystallites via phase separation reaction and the removal of defect-related absorption centers during annealing. Copyright © 2009 American Scientific Publishers All rights reserved.

Research Area(s)

  • Photoluminescence, Raman., Si nanocrystals