Effect of diamagnetic barium substitution on magnetic and photovoltaic properties in multiferroic BiFeO3

• Published in: Journal of applied physics 2014-05, Vol.115 (17)
• Main Authors: Hung, C.-M., Tu, C. S., Xu, Z.-R., Chang, L.-Y., Schmidt, V. H., Chien, R. R., Chang, W. C.
• Format: Article
• Language: English
• Subjects: Barium; Bismuth ferrite; Ceramics; Circuits; Current voltage characteristics; Diamagnetism; Energy conversion efficiency; Ferromagnetic materials; Heterostructures; Indium tin oxides; Light; Luminous intensity; Magnetic properties; Magnetization; Maximum power; Open circuit voltage; Perovskites; Photovoltaic cells; Short circuit currents; Solar cells; Substitutes; Unit cell
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.4862381

Spontaneous magnetization and photovoltaic (PV) effects have been measured in (Bi1-xBax)FeO3-δ ceramics for x = 0.05, 0.10, and 0.15. The substitution of Ba2+ ion in the A site of the perovskite unit cell can effectively enhance the ferromagnetic magnetization. The heterostructure of indium tin oxide (ITO) film/(Bi1-xBax)FeO3-δ ceramic/Au film exhibits significant PV effects under illumination of λ = 405 nm. The PV responses decrease with increasing Ba concentration. The maximum power-conversion efficiency in the ITO/(Bi0.95Ba0.5)FeO2.95/Au can reach 0.006%. A theoretical model based on optically excited current in the depletion region between ITO film and (Bi1-xBax)FeO3-δ ceramics is used to describe the I-V characteristic, open-circuit voltage (Voc), and short-circuit current density (Jsc) as a function of light intensity.