Out-of-plane (c-axis) HRXRD pattern in θ–2θ geometry for LSTO films. The epitaxial growth of films is clearly seen. Inset shows the shift in (200) peak position for films A and B annealed, respectively, in Ar/H2 and Ar ambients.
RBS spectra of the LSTO film. The symbols correspond to the experimental data, and the solid line to the simulated curve. The high energy edges corresponding to the constituent elements of the film are marked.
Temperature variation of electrical conductivity of the films.
Temperature dependence of Seebeck coefficient of the films. The linear fits to the low temperature region based on Eq. (2), assuming a degenerate conduction mechanism are also shown. Inset shows the variation of Seebeck coefficient with log T. The slopes of the linear fits are around −298 μV K−1 decade−1 due to the setting in of a non-degenerate conduction mechanism at intermediate temperatures. The deviation at higher temperatures is due to the oxidation/reduction of the films depending on the ambient.
Measured and simulated SE curves in the range 300–2100 nm for films A and B. Open circles correspond to the measured ψ, open rectangles to the measured Δ, while the lines correspond to the simulated curves for the three different incident angles (60,° 65,° and 70°).
Extracted n and k as a function of wavelength for the films.
Calculated power factor-temperature product of the films as a function of temperature.
Thermoelectric and optical properties of LSTO films at 295 K. The optical band gap (Eg), electrical conductivities measured directly (σDC ) and extracted from SE modeling (σopt ), ratio of effective mass to rest mass of electron (m*/m0), carrier density (n), mobility (μ), relaxation time (τ), mean free path of carriers (l), density of states of the conduction band (Nc ), and Seebeck coefficients (S) are presented.
Fitting parameters for the Drude -Lorentz dispersion relation (Eq. (5)) with two Lorentz oscillators for the films. The high frequency dielectric constant (ε ∞), plasma frequency (ωp ), damping constant (Γ τ ) of plasmons and amplitude (Ak ), energy (Ek ), and damping (Ck ) of the kth harmonic oscillator are presented.
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