Synthesis and Characterization of Cu-doped ZnO Film in Nanowire like Morphology Using Low Temperature Self-Catalytic Vapor-Liquid-Solid (VLS) Method

Autor: Daniel Vanhart, Alok C. Rastogi, In-Tae Bae, Ratheesh R. Thankalekshmi, Samwad Dixit
Rok vydání: 2012
Předmět:
Zdroj: MRS Proceedings. 1494:37-42
ISSN: 1946-4274
0272-9172
DOI: 10.1557/opl.2012.1696
Popis: Cu-doped ZnO film in nanowire structure is synthesized by a closed space flux sublimation and periodic oxidation method at ∼300°C over Si substrate. Oxidative process controlled selfcatalytic VLS mechanism is proposed for the film growth. X-ray diffraction pattern establishes that Cu-doped ZnO nanowires retain the crystallite structure of the wurtzite ZnO. TEM studies indicate single crystal character of the Cu-doped ZnO nanowires. Optical absorption analysis of Cu-doped ZnO nanowires defines two direct energy band gaps. The low energy band gap at 3.2eV is intrinsic to the Cu-doped ZnO material. The higher energy band gap at 3.5eV is attributed to the nanosize, mediated by strong forward scattering of light from the nanowires. Sharp photoluminescence in Cu-doped ZnO corresponding to near bandgap free exciton emission is observed and a redshift of ∼0.07 eV is consistent with the effect of Cu-doping. The visible emission band in both ZnO and Cu-doped ZnO shows a broad green emission band with Cu-substitution shifting the maximum visible luminescence towards the higher energy side.
Databáze: OpenAIRE
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