Repositório Institucional da Universidade de Aveiro > Departamento de Física > FIS - Artigos >
 ZnO homoepitaxy on the O polar face of hydrothermal and melt-grown substrates by pulsed laser deposition
Please use this identifier to cite or link to this item http://hdl.handle.net/10773/5676

title: ZnO homoepitaxy on the O polar face of hydrothermal and melt-grown substrates by pulsed laser deposition
authors: Rogers, D. J.
Hosseini Teherani, F.
Largeteau, A.
Demazeau, G.
Moisson, C.
Turover, D.
Nause, J.
Garry, G.
Kling, R.
Gruber, T.
Waag, A.
Jomard, F.
Galtier, P.
Lusson, A.
Monteiro, T.
Soares, M. J.
Neves, A.
Carmo, M. C.
Peres, M.
Lerondel, G.
Hubert, C.
keywords: Hydrothermal and melt-grown ZnO crystals
ZnO films grown by PLD
structural and optical properties
issue date: Apr-2007
publisher: Springer Verlag
abstract: 2 cm diameter hydrothermal ZnO crystals were grown and then made into substrates using both mechanical and chemical-mechanical polishing (CMP). CMP polishing showed superior results with an (0002) Ω scan full width half maximum (FWHM) of 67 arcsec and an root mean square (RMS) roughness of 2 °A. In comparison, commercial melt-grown substrates exhibited broader X-ray diffraction (XRD) linewidths with evidence of sub-surface crystal damage due to polishing, including a downward shift of c-lattice parameter. Secondary ion mass spectroscopy revealed strong Li, Fe, Co, Al and Si contamination in the hydrothermal crystals as opposed to the melt-grown substrates, for which glow discharge mass spectroscopy studies had reported high levels of Pb, Fe, Cd and Si. Low temperature photoluminescence (PL) studies indicated that the hydrothermal crystal had high defect and/or impurity concentrations compared with the melt-grown substrate. The dominant bound exciton for the melt-grown substrate was indexed to Al. ZnO films were grown using pulsed laser deposition. Themelt-grown substrates gave superior results with XRD (0002) Ω and 2θ/Ω WHM of 124 and 34 arcsec, respectively. Atomic force microscope measurements indicated a low RMS roughness (1.9 nm) as confirmed by fringes in the XRD 2θ/Ω scan. It was suggested that the improvement in XRD response relative to the substrate might be due to “healing” of sub-surface polishing damage due to the elevated Ts used for the growth. Indeed the c-lattice parameter for the homoepitaxial layer on the melt-grown substrate had become that which would be expected for strain-free ZnO. Furthermore, the stability of the PL peak positions relative to bulk ZnO, confirmed that the films appear practically strain free.
URI: http://hdl.handle.net/10773/5676
ISSN: 0947-8396
source: Applied Physics A: Materials Science and Processing
appears in collectionsFIS - Artigos
I3N - Artigos

files in this item

file description sizeformat
APLA.pdfversão pdf do editor680.56 kBAdobe PDFview/open
Restrict Access. You can Request a copy!

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


Valid XHTML 1.0! RCAAP OpenAIRE DeGóis
ria-repositorio@ua.pt - Copyright ©   Universidade de Aveiro - RIA Statistics - Powered by MIT's DSpace software, Version 1.6.2