Optical properties of ferroelectricBi4Ti3O12

Optical anisotropy in bismuth titanate: An experimental and theoretical study

“…This substantiates that BiT is an indirect band gap semiconductor, in agreement with our previous work 24 and several other experiments 19,43 and first-principles calculations. 27 Upon fitting our absorption data using Eq. (1), we obtained energy band gap of the order of E g ¼ 3.57 6 0.01 eV and E g ¼ 3.54 6 0.02 eV for (001) and (118) oriented films, respectively, which are consistent with previously reported data.…”

“…Here, first-principles density functional calculations would be useful since such study could shed a detailed insight into the origin of optical property, as shown previously for a number of oxides. 20,[27][28][29] Though considerable attention has been paid toward the experimental studies of optical and dielectric properties of BiT, 15,17,19 very few reports provide a microscopic understanding of the optical properties using first-principles calculations. Among the few reports, Cai et al 30 based on the bond orbital theory concluded that the large nonlinear refractive index of ferroelectric BiT is due to virtual electronic excitation from the filled valence band (VB) to the empty cationic d-orbital at short equilibrium bond lengths.…”

“…Recently, optical properties of ferroelectric bismuth titanate have been calculated using TBmBJ functional using a smaller cell with space group Pc (Ref. 27) where close proximity between the experimental and calculated band gap was found; however, orientation dependence of optical behavior was not discussed. In this manuscript, we show the results of ellipsometric measurements on epitaxial bismuth titanate thin films of two different orientations grown on (100) and (110) oriented strontium titanate (STO) substrates using pulsed laser deposition.…”

Transparent conducting properties of SrSnO3 and ZnSnO3

“…45 This functional gives greatly improved band gaps for simple insulators and semiconductors when compared to conventional semilocal density functionals. [45][46][47][48][49] The TB-mBJ functional gives good agreement with experimental band gaps for simple oxides, including ferroelectric transition metal oxides such as Bi 4 Ti 3 O 12 , 50 but does not correctly treat correlated oxides, such as antiferromagnetic Mott insulators. 48,49 Doping was treated keeping the crystal structure fixed and employing the virtual crystal approximation (VCA), which is an average potential approximation.…”

Energy resolution and related charge carrier mobility in LaBr3:Ce scintillators

“…11,12 In spite of all the efforts, [13][14][15][16][17] some aspects of the conversion mechanism are still unclear. For example, energy resolution of inorganic scintillators is still much larger than the fundamental limit dictated by photon statistics.…”