Tunable band gap in Bi(Fe1−xMnx)O3 films

Abstract

In order to investigate band gap tunability in polar oxides, we measured the optical properties of a series of Bi͑Fe 1−x Mn x ͒O 3 thin films. The absorption response of the mixed metal solid solutions is approximately a linear combination of the characteristics of the two end members, a result that demonstrates straightforward band gap tunability in this system.

Device Performance of the Mott InsulatorLaVO3as a Photovoltaic Material

“…Therefore, for future TMO-based light absorbers, the band gap should be not only optimal for solar harvesting but also direct in nature. A few other TMOs with compatible structures including BiMnO 3 (1.1 eV) [39], YBa 2 Cu 3 O 6 (1.5 eV) [72], La 2 CuO 4 (1.72 eV), and Sm 2 CuO 4 (1.27 eV) [12] could satisfy these two requirements and are worth exploring in the future. Another promising approach is to use narrow-band-gap Mott insulators.…”

“…4(a), the absorption of LVO is significantly higher than that of crystalline silicon (c-Si) in the visible range and even compares favorably with CdTe and amorphous silicon (a-Si) at long wavelengths, indicating that LVO is promising for harvesting solar light. We also grow LVO films on quartz and LSAO(001) substrates, yielding Figure 4(b) shows the Tauc plots of ðαEÞ 2 and ðαEÞ 1=2 versus E, which are used to determine the nature and size of the band gap [39,40]. The ðαEÞ 1=2 versus E plot displays a sharp and linear rise above the absorption edge, and the linear extrapolation of this curve to zero yields an indirect gap of 1.08 eV.…”

Spin cycloid quenching in Nd3+-substituted BiFeO3

“…One way forward is to select a parent compound with several desirable characteristics and to employ chemical or physical tuning to bring in the missing features. Chemical substitution is a wellknown strategy for tuning the physical properties of a material [3][4][5][6][7][8] and is a promising route for achieving the desired multifunctionality 9,10 . This strategy is backed by the recent prediction that a magnetic ion placed on the perovskite "A site" may activate ferroelectrically-induced ferromagnetism due to coupling between the Jahn-Teller distortion and weak canting 11,12 .…”

“…BiFeO 3 displays an R3c lattice 17 that is very amenable to chemical substitution 18 . Among the many types of substitution under investigation 4,5,7,18,19 , those that yield both ferroelectricity and ferromagnetism are especially attractive due to possible magnetoelectric device applications 20 . Bi 1−x Nd x FeO 3 in the range of 0.15≤x≤0.175 is a physical realization of this important case 18 .…”

Photoelectrochemical Performance Observed in Mn-Doped BiFeO3 Heterostructured Thin Films

“…The A-site and B-site represents the positions of Bi and Fe atoms in the BFO lattice, respectively. B-site Mn doping is a potential method of modifying the band structure of BFO [17]. The Mn element has attracted great attention due to its special role in BFO thin films.…”