Prominent ferroelectric properties in Mn-doped BiFeO3 spin-coated thin films

BiFe1-xMnxO3 (BFMO, x = 0-0.05) thin films were successfully deposited onto fluorine-doped tin oxide (FTO)/glass substrates via sol-gel technique. According to results obtained from XRD, Raman spectroscopy, SEM, and energy-dispersive EDS, it was found that films have rhomboid perovskite structure and Mn ions were successfully and uniformly incorporated into BiFeO3 (BFO) films. Doping process was accompanied by the reduction in grain size. From XPS pattern, it was found that both Fe2+ concentration and oxygen vacancies are reduced as a result of Mn doping. Compared with pure BFO samples, ferroelectric, dielectric, and optical properties of BFMO films are noticeably enhanced. BiFe0.96Mn0.04O3 film exhibited excellent remnant polarization (2Pr of 312 mu C/cm2) accompanied by a low leakage current. Underlying mechanism can be explained in terms of Mn doping-induced structural transition, reduction in grain size, and oxygen vacancies. Additionally, increased bandgap (Eg = 2.68 eV) was obtained in BiFe0.98Mn0.02O3 film compared with BFO film (Eg = 2.58 eV). This work demonstrates remarkable effect of Mn doping on BFO, indicating that BFMO is promising candidate for ferroelectric photovoltaic device applications. (c) 2021 Elsevier B.V. All rights reserved.

Automated summary

BFMO thin films were successfully deposited on FTO/glass substrates via sol-gel technique, with Mn doping showing significant enhancement in properties compared to pure BFO samples. The Mn doping-induced changes in structure, grain size reduction, and oxygen vacancies were identified as underlying mechanisms for the improved performance of BFMO films, making them promising for ferroelectric photovoltaic device applications.