Optical signatures of defects in BiFeO${}_3$

Abstract

Optical absorption in rhombohedral BiFeO${}_3$ starts at photon energies below the photoemission band gap of $\approx$ 3 eV calculated from first principles. A shoulder at the absorption onset has so far been attributed to low-lying electronic transitions or to oxygen vacancies. In this work optical spectra are calculated ab initio to determine the nature of the optical transitions near the absorption onset of pristine BiFeO${}_3$, the effect of electron-hole interaction, and the spectroscopic signatures of typical defects, i.e. doping (excess electrons or holes), intrinsic defects (oxygen and bismuth vacancies), and low-energy structural defects (ferroelectric domain walls).

References in corpus (4)

• Very large spontaneous electric polarization in BiFeO3 single crystals at room temperature and its evolution under cycling fields
• Influence of strain and oxygen vacancies on the magnetoelectric properties of multiferroic bismuth ferrite
• Conduction at domain walls in insulating Pb(Zr${}_{0.2}$Ti${}_{0.8}$)O${}_3$ thin films
• Linear and Nonlinear Optical constants of BiFeO_3

Cited by in corpus (2)

• Understanding electronic excited states in BiFeO${}_3$ via ab initio calculations and symmetry analysis
• Energy profile and hopping barriers for small electron polarons at ferroelectric domain walls in bismuth ferrite from first principles