Thin-film growth and photovoltaic cell fabrication
Ferroelectric, dielectric, and photovoltaic measurements
PFM measurement
Transient reflectivity spectroscopy
Computational modeling
The spectroscopic ellipsometry measurements were performed using a commercially available rotating analyzer instrument with compensator (V-VASE; J.A. Woollam Co. Inc.) within the spectral range from 0.6 to 6.5 eV. Data were collected at two angles of incidence (50° and 70°), and the complex dielectric function was determined on a wavelength-by-wavelength basis using a three-layer model comprising surface roughness, the La-substituted BFO, and the STO substrate (49). The absorption coefficient was then calculated from the dielectric function.