Kalimuthu, Vijayarangamuthu and Kumar, Praveen and Kumar, Mahesh and Rath, Shyama (2018) Growth mechanism and optical properties of Ge nanocrystals embedded in a GeO (x) matrix. Applied Physics A: Materials Science and Processing , 124 (10). pp. 712-719. ISSN 0947-8396

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Abstract

Quantum confined germanium (Ge) nanocrystals were synthesized by a thermal annealing of germanium oxide thin films fabricated by an e-beam evaporation method. The nanocrystal formation, structure, and sizes upon annealing are evaluated by a combination of X-ray diffraction, transmission electron microscopy, and Raman spectroscopy studies. Spherical nanocrystals with sizes of around 3 nm and having both diamond and tetragonal phases are formed for an annealing temperature of 500 A degrees C. The thermally induced transformation and phase separation of amorphous germanium oxide to nanocrystalline Ge is discussed using X-ray photoelectron spectroscopy. The bandgap agrees with the calculated values using effective mass approximation. The visible photoluminescence is investigated as a function of the annealing temperature. This disproportionation mechanism of germanium oxide films showing favorable optical properties suggests its scope for forming quantum confined Ge nanocrystals embedded in its amorphous matrix relevant for both electronic and optoelectronic applications.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Springer Verlag.
Subjects:	Materials Science Applied Physics/Condensed Matter
Divisions:	UNSPECIFIED
Depositing User:	Mr. Yogesh Joshi
Date Deposited:	21 Nov 2019 07:16
Last Modified:	21 Nov 2019 07:16
URI:	http://npl.csircentral.net/id/eprint/3908

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