Valence band offset at GaN/beta-Si3N4 and beta-Si3N4/Si(111) heterojunctions formed by plasma-assisted molecular beam epitaxy

Kumar, Mahesh and Roul, Basanta and Bhat, Thirumaleshwara N and Rajpalke, Mohana K and Kalghatgi, AT and Krupanidhi, SB (2012) Valence band offset at GaN/beta-Si3N4 and beta-Si3N4/Si(111) heterojunctions formed by plasma-assisted molecular beam epitaxy. In: THIN SOLID FILMS, 520 (15). pp. 4911-4915.

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Abstract

Ultra thin films of pure beta-Si3N4 (0001) were grown on Si (111) surface by exposing the surface to radio- frequency nitrogen plasma with a high content of nitrogen atoms. Using beta-Si3N4 layer as a buffer layer, GaN epilayers were grown on Si (111) substrate by plasma-assisted molecular beam epitaxy. The valence band offset (VBO) of GaN/beta-Si3N4/ Si heterojunctions is determined by X-ray photoemission spectroscopy. The VBO at the beta-Si3N4 /Si interface was determined by valence-band photoelectron spectra to be 1.84 eV. The valence band of GaN is found to be 0.41 +/- 0.05 eV below that of beta-Si3N4 and a type-II heterojunction. The conduction band offset was deduced to be similar to 2.36 eV, and a change of the interface dipole of 1.29 eV was observed for GaN/ beta-Si3N4 interface formation. (c) 2011 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	THIN SOLID FILMS
Publisher:	ELSEVIER SCIENCE SA
Additional Information:	Copyright for this article belongs to the Elsevier Science
Keywords:	Nitrides;Molecular beam epitaxy;X-ray photo-emission spectroscopy
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	27 Jun 2012 07:55
Last Modified:	27 Jun 2012 07:55
URI:	http://eprints.iisc.ac.in/id/eprint/44738

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