Amorphization and reduction of thermal conductivity in porous silicon by irradiation with swift heavy ions

Journal Article · Sun Jul 07 00:00:00 EDT 2013 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4812280· OSTI ID:22122787

Newby, Pascal J. ^[1]; Canut, Bruno; Bluet, Jean-Marie; Lysenko, Vladimir ^[1]; Gomes, Severine ^[2]; Isaiev, Mykola; Burbelo, Roman ^[3]; Termentzidis, Konstantinos ^[4]; Chantrenne, Patrice ^[5]; Frechette, Luc G. ^[6]

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1. Institut des Nanotechnologies de Lyon, Universite de Lyon, INL-UMR5270, CNRS, INSA de Lyon, Villeurbanne 69621 (France)
2. Centre de Thermique de Lyon, Universite de Lyon, CETHIL-UMR5008, CNRS, INSA de Lyon, Villeurbanne 69621 (France)
3. Faculty of Physics, Taras Shevchenko National University of Kyiv, 64/13, Volodymyrs'ka St., Kyiv 01601 (Ukraine)
4. Laboratoire LEMTA, Universite de Lorraine-CNRS UMR 7563, 54506 Vandoeuvre-les-Nancy cedex (France)
5. Universite de Lyon, INSA de Lyon, MATEIS-UMR CNRS 5510, Villeurbanne 69621 (France)
6. Institut Interdisciplinaire d'Innovation Technologique (3IT), Universite de Sherbrooke, CNRS UMI-LN2, Sherbrooke, Quebec J1K0A5 (Canada)

In this article, we demonstrate that the thermal conductivity of nanostructured porous silicon is reduced by amorphization and also that this amorphous phase in porous silicon can be created by swift (high-energy) heavy ion irradiation. Porous silicon samples with 41%-75% porosity are irradiated with 110 MeV uranium ions at six different fluences. Structural characterisation by micro-Raman spectroscopy and SEM imaging show that swift heavy ion irradiation causes the creation of an amorphous phase in porous Si but without suppressing its porous structure. We demonstrate that the amorphization of porous silicon is caused by electronic-regime interactions, which is the first time such an effect is obtained in crystalline silicon with single-ion species. Furthermore, the impact on the thermal conductivity of porous silicon is studied by micro-Raman spectroscopy and scanning thermal microscopy. The creation of an amorphous phase in porous silicon leads to a reduction of its thermal conductivity, up to a factor of 3 compared to the non-irradiated sample. Therefore, this technique could be used to enhance the thermal insulation properties of porous Si. Finally, we show that this treatment can be combined with pre-oxidation at 300 Degree-Sign C, which is known to lower the thermal conductivity of porous Si, in order to obtain an even greater reduction.

• OSTI ID: 22122787
• Journal Information: Journal of Applied Physics, Vol. 114, Issue 1; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AMORPHOUS STATE
HEAVY IONS
INTERACTIONS
ION BEAMS
IRRADIATION
MEV RANGE 100-1000
NANOSTRUCTURES
OXIDATION
PHYSICAL RADIATION EFFECTS
POROUS MATERIALS
RAMAN SPECTRA
RAMAN SPECTROSCOPY
SCANNING ELECTRON MICROSCOPY
SEMICONDUCTOR MATERIALS
SILICON
THERMAL CONDUCTIVITY
THERMAL INSULATION
URANIUM IONS