Raman Vibrations, Domain Structures, and Photovoltaic Effects in A‐Site La‐Modified BiFeO 3 Multiferroic Ceramics
| Autor: | Chun-Yen Lin, Cheng-Sao Chen, Zhe-Rui Xu, Chi-Shun Tu, Yves Idzerda, Ming-Quan Lyu, Ting-Shan Chan, Pin-Yi Chen, V. Hugo Schmidt |
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| Rok vydání: | 2015 |
| Předmět: |
010302 applied physics
Materials science Valence (chemistry) Absorption spectroscopy Band gap Analytical chemistry Heterojunction 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Indium tin oxide symbols.namesake Molecular geometry 0103 physical sciences Materials Chemistry Ceramics and Composites symbols 0210 nano-technology Raman spectroscopy Spectroscopy |
| Zdroj: | Journal of the American Ceramic Society. 99:674-681 |
| ISSN: | 1551-2916 0002-7820 |
| DOI: | 10.1111/jace.13983 |
| Popis: | Micro-Raman spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy (TEM), oxygen vacancies, synchrotron X-ray absorption spectroscopy, magnetizations, optical band gaps, and photovoltaic (PV) effects have been studied in (Bi1−xLax)FeO3 (BFO100xL) ceramics for x = 0.0, 0.05, 0.10, and 0.15. XRD, Raman spectra, and TEM confirm a rhombohedral R3c symmetry with the tilted FeO6 oxygen octahedra in all compounds. The low-frequency Raman vibrations become broader and shift toward higher frequency as La3+ increases. Fe K-edge synchrotron X-ray absorptions reveal that Fe3+ valence and Fe–O–Fe bond angle are not modified by the La3+ substitution. All compounds exhibit a linear antiferromagnetic feature. Optical transmission reveals band gaps in the range of 2.22–2.24 eV. The heterostructures of indium tin oxide (ITO) film/(Bi1−xLax)FeO3 ceramics/Au film show a p–n junction-like I–V characteristic behavior. The maximal PV power conversion efficiency can reach 0.19% in ITO/BFO15L/Au under illumination of λ = 405 nm. A junction-like theoretical model can reasonably describe open-circuit voltage and short-circuit current as a function of illumination intensity. |
| Databáze: | OpenAIRE |
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