Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/72385
Título: | The role of Ga and Bi doping on the local structure of transparent zinc oxide thin films |
Autor(es): | Correia, Filipe Costa Ribeiro, Joana Margarida Fernandes Silva Kuzmin, Alexei Pudza, I. Kalinko, A. Welter, Edmund Mendes, Adelio Rodrigues, Joana Sedrine, Nabiha Ben Monteiro, Teresa Correia, Maria Rosário Tavares, C. J. |
Palavras-chave: | Zinc oxide Thin films Sputtering Thermoelectric X-ray absorption spectroscopy Raman spectroscopy |
Data: | 2021 |
Editora: | Elsevier 1 |
Revista: | Journal of Alloys and Compounds |
Citação: | Correia, F. C., Ribeiro, J. M., Kuzmin, A., et. al. (2021). The role of Ga and Bi doping on the local structure of transparent zinc oxide thin films. Journal of Alloys and Compounds, 870, 159489. |
Resumo(s): | Transparent undoped ZnO and additionally doped with Ga and Bi thin films were produced by magnetron sputtering. The thin films were comprehensively characterized by X-ray absorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission and scanning transmission electron (TEM, STEM) microscopy and Raman spectroscopy. All undoped and doped films crystallise in a ZnO phase with the hexagonal wurtzite crystal structure. The local structure of the thin films was investigated by temperature-dependent X-ray absorption spectroscopy at the Zn and Ga K-edges, as well as at the Bi L3-edge. It was found that the doping of Ga3+ and Bi3+ ions in the ZnO wurtzite structure produces distinct effects on the thin film microstructure. The substitution of Zn2+ ions by smaller Ga3+ ions introduces a static disorder to the thin film structure, which is evidenced by an increase in the mean-square relative displacements σ2(Zn‒O) and σ2(Zn‒Zn). At the same time, large Bi3+ ions do not substitute zinc ions, but are likely located in the disordered environment at the ZnO grain boundaries. This conclusion was directly supported by energy-dispersive X-ray spectroscopy combined with TEM and STEM observations as well as by resonant and non-resonant μ-Raman experiments at room temperature, where the ZnO and ZnO:Bi spectra are similar, suggesting a lack of structural disorder in the wurtzite cell. On the other hand, the Raman disorder-activated phonon is pronounced for Ga-doping of the ZnO lattice, confirming the compositional disorder. Both XRD and XPS ruled out Ga2O3 phase in Ga-doped ZnO; conversely, Bi2O3 and a small amount of Bi‒metal phases are clearly discerned by XPS experiments, further suggesting that Bi is not incorporated in the ZnO wurtzite cell, but segregated to grain boundaries. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/72385 |
DOI: | 10.1016/j.jallcom.2021.159489 |
ISSN: | 0925-8388 |
Versão da editora: | https://www.sciencedirect.com/science/article/pii/S0925838821008987 |
Arbitragem científica: | yes |
Acesso: | Acesso restrito UMinho |
Aparece nas coleções: | BUM - CIÊNCIAVITAE |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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2021-JALCOM_CJT.pdf Acesso restrito! | 7,09 MB | Adobe PDF | Ver/Abrir |