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Rolling dopant and strain in Y-doped BiFeO(3) epitaxial thin films for photoelectrochemical water splitting

We report significant photoelectrochemical activity of Y-doped BiFeO(3) (Y-BFO) epitaxial thin films deposited on Nb:SrTiO(3) substrates. The Y-BFO photoanodes exhibit a strong dependence of the photocurrent values on the thickness of the films, and implicitly on the induced epitaxial strain. The pe...

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Detalles Bibliográficos
Autores principales: Haydous, F., Scarisoreanu, N. D., Birjega, R., Ion, V., Lippert, T., Dumitrescu, N., Moldovan, A., Andrei, A., Teodorescu, V. S., Ghica, C., Negrea, R., Dinescu, M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6202420/
https://www.ncbi.nlm.nih.gov/pubmed/30361505
http://dx.doi.org/10.1038/s41598-018-34010-9
Descripción
Sumario:We report significant photoelectrochemical activity of Y-doped BiFeO(3) (Y-BFO) epitaxial thin films deposited on Nb:SrTiO(3) substrates. The Y-BFO photoanodes exhibit a strong dependence of the photocurrent values on the thickness of the films, and implicitly on the induced epitaxial strain. The peculiar crystalline structure of the Y-BFO thin films and the structural changes after the PEC experiments have been revealed by high resolution X-ray diffraction and transmission electron microscopy investigations. The crystalline coherence breaking due to the small ionic radius Y-addition was analyzed using Willliamson-Hall approach on the 2θ-ω scans of the symmetric (00 l) reflections and confirmed by high resolution TEM (HR-TEM) analysis. In the thinnest sample the lateral coherence length (L(∥)) is preserved on larger nanoregions/nanodomains. For higher thickness values L(∥) is decreasing while domains tilt angles (α(tilt)) is increasing. The photocurrent value obtained for the thinnest sample was as high as J(ph) = 0.72 mA/cm(2), at 1.4 V(vs. RHE). The potentiostatic scans of the Y-BFO photoanodes show the stability of photoresponse, irrespective of the film’s thickness. There is no clear cathodic photocurrent observation for the Y-BFO thin films confirming the n-type semiconductor behavior of the Y-BFO photoelectrodes.