Growth of silicon quantum dots by oxidation of the silicon nanocrystals embedded within silicon carbide matrix

Journal Article · Wed Oct 15 00:00:00 EDT 2014 · AIP Advances

DOI:https://doi.org/10.1063/1.4897378· OSTI ID:22300231

Kole, Arindam; Chaudhuri, Partha ^[1]

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1. Indian Association for the Cultivation of Science, 2A and 2B Raja S.C. Mullick Road, Jadavpur, Kolkata-700032 (India)

A moderately low temperature (≤800 °C) thermal processing technique has been described for the growth of the silicon quantum dots (Si-QD) within microcrystalline silicon carbide (μc-SiC:H) dielectric thin films deposited by plasma enhanced chemical vapour deposition (PECVD) process. The nanocrystalline silicon grains (nc-Si) present in the as deposited films were initially enhanced by aluminium induced crystallization (AIC) method in vacuum at a temperature of T{sub v} = 525 °C. The samples were then stepwise annealed at different temperatures T{sub a} in air ambient. Analysis of the films by FTIR and XPS reveal a rearrangement of the μc-SiC:H network has taken place with a significant surface oxidation of the nc-Si domains upon annealing in air. The nc-Si grain size (D{sub XRD}) as calculated from the XRD peak widths using Scherrer formula was found to decrease from 7 nm to 4 nm with increase in T{sub a} from 250 °C to 800 °C. A core shell like structure with the nc-Si as the core and the surface oxide layer as the shell can clearly describe the situation. The results indicate that with the increase of the annealing temperature in air the oxide shell layer becomes thicker and the nc-Si cores become smaller until their size reduced to the order of the Si-QDs. Quantum confinement effect due to the SiO covered nc-Si grains of size about 4 nm resulted in a photoluminescence peak due to the Si QDs with peak energy at 1.8 eV.

• OSTI ID: 22300231
• Journal Information: AIP Advances, Vol. 4, Issue 10; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
CRYSTALLIZATION
CRYSTALS
DEPOSITS
FOURIER TRANSFORMATION
GRAIN SIZE
INFRARED SPECTRA
OXIDATION
PHOTOLUMINESCENCE
PLASMA
QUANTUM DOTS
SILICON
SILICON CARBIDES
SILICON OXIDES
THIN FILMS
X-RAY DIFFRACTION
X-RAY PHOTOELECTRON SPECTROSCOPY