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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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|
|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|
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