TY - JOUR
T1 - Ferroelectric Oxides with Strong Visible-Light Absorption from Charge Ordering
AU - He, Jiangang
AU - Franchini, Cesare
AU - Rondinelli, James M.
N1 - Funding Information:
Work at the University of Vienna was sponsored by the FWF-SFB project VICOM (Grant No. F41). J.M.R. was supported by the U.S. DOE Office of Basic Energy Sciences, under grant no. DE-AC02-06CH11357 and a 3M Non-Tenured Faculty Award. All calculations were performed on the Vienna Scientific Cluster (VSC).
PY - 2017/3/28
Y1 - 2017/3/28
N2 - The applications of transition metal oxides as photovoltaic and photocatalytic materials are mainly impeded by their poor visible light absorption, low photogenerated carrier mobility, and low valence band position, which originate from the generally large band gap (≥3 eV), narrow transition metal d states, and deep oxygen 2p states. Here, we conceive a design strategy to realize small band gap polar oxides with high carrier mobilities by combining small radii A cations with Bi3+/Bi5+ charge disproportion. We show that these cation sizes and chemical features shift the valence band edge to higher energies and therefore reduce the band gap, promoting the formation of highly dispersive Bi 6s states near the Fermi level as a byproduct. By means of advanced many-electron-based first-principles calculations, we predict a new family of thermodynamically stable/metastable polar oxides ABiO3 (A = Ca, Cd, Zn, and Mg), which adopt the Ni3TeO6-type (space group R3) structure and exhibit optical band gaps of ∼2.0 eV, as promising single phase photovoltaic and photocatalytic materials operating in the visible light spectrum.
AB - The applications of transition metal oxides as photovoltaic and photocatalytic materials are mainly impeded by their poor visible light absorption, low photogenerated carrier mobility, and low valence band position, which originate from the generally large band gap (≥3 eV), narrow transition metal d states, and deep oxygen 2p states. Here, we conceive a design strategy to realize small band gap polar oxides with high carrier mobilities by combining small radii A cations with Bi3+/Bi5+ charge disproportion. We show that these cation sizes and chemical features shift the valence band edge to higher energies and therefore reduce the band gap, promoting the formation of highly dispersive Bi 6s states near the Fermi level as a byproduct. By means of advanced many-electron-based first-principles calculations, we predict a new family of thermodynamically stable/metastable polar oxides ABiO3 (A = Ca, Cd, Zn, and Mg), which adopt the Ni3TeO6-type (space group R3) structure and exhibit optical band gaps of ∼2.0 eV, as promising single phase photovoltaic and photocatalytic materials operating in the visible light spectrum.
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U2 - 10.1021/acs.chemmater.6b03486
DO - 10.1021/acs.chemmater.6b03486
M3 - Article
AN - SCOPUS:85016446231
VL - 29
SP - 2445
EP - 2451
JO - Chemistry of Materials
JF - Chemistry of Materials
SN - 0897-4756
IS - 6
ER -