A modified model of metal-semiconductor contacts is applied to analyze the capacitance-voltage and current-voltage characteristics of metal-ferroelectric-metal structures. The ferroelectric polarization is considered as a sheet of surface charge situated at a fixed distance from the interface. The presumable high concentration of structural defects acting as active electric traps is taken into account by introducing a deep acceptorlike level. The model is applied on a set of metal-$\mathrm{Pb}(\mathrm{Zr},\mathrm{Ti}){\mathrm{O}}_3$ -metal samples with different $\mathrm{Zr}∕\mathrm{Ti}$ ratios, deposited by different methods, and having different thicknesses, electrode materials, and electrode areas. Values around ${10}^{18}{\mathrm{cm}}^{-3}$ were estimated for the hole concentration from capacitance-voltage measurements. The space-charge density near the electrode, estimated from current-voltage measurements, is in the ${10}^{20}–{10}^{21}{\mathrm{cm}}^{-3}$ range. The total thickness of the interface layer ranges from $3\text{to}35\mathrm{nm}$ , depending on the $\mathrm{Zr}∕\mathrm{Ti}$ ratio, on the shape of the hysteresis loop, and on the electrode material. The simulated $I\text{-}V$ characteristics is fitted to the experimental one using the potential barrier and Richardson’s constant as parameters. The potential barrier is determined to be in the $1.09–1.37\mathrm{eV}$ range and Richardson’s constant is $520\mathrm{A}{\mathrm{cm}}^{-2}{\mathrm{K}}^{-2}$ .

Asymmetric metal–ferroelectric–metal (MFM) structures were manufactured by sol–gel deposition of a lead zirconate-titanate (PZT with Zr/Ti ratio 65/35) film on Pt-coated Si, with a Au top electrode. The average remnant polarization of 9 μC/cm² and the coercive field of 39 kV/cm were obtained from the hysteresis loop measurements. A detailed analysis of the polarization–electric field $\mathrm{(P–E),}$ capacitance–voltage $\mathrm{(C–V),}$ and current–voltage $\mathrm{(I–V)}$ measurement results allowed us to estimate the near-electrode space-charge region thickness (roughly half of the film thickness at zero voltage), net doping concentration (around ${10}^{18}\hspace{0.17em}{\mathrm{cm}}^{\text{−3}}\mathrm{),}$ built-in potential (in the 0.4–0.8 V range, depending on the injecting electrode), and dynamic dielectric constant (5.2). The current logarithm–voltage dependence for the field-enhanced Schottky emission obeys a “1/4” law. The spectral distribution of the short circuit current measured under continuous light illumination in the 290–800 nm range exhibits a cutoff wavelength at 370 nm and a maximum sensitivity at about 340 nm. The estimated band-gap energy of the PZT material is 3.35 eV. The MFM structure is discussed in terms of two back-to-back Schottky diodes with a ferroelectric material in between. It is concluded that the semiconductor properties of the films are not negligible and, in certain conditions, are dominating over the ferroelectric ones.

This paper reports on the development and spectral analysis of Sm³⁺ (1.0%) and Dy³⁺ (1.0%) doped lithium-boro-tellurite glasses. Abright orange (⁴G_5/2→⁶H_7/2) along with a red (⁴G_5/2→⁶H_9/2) and a yellow (⁴G_5/2→⁶H_5/2) emission transition have been measured from Sm³⁺ doped lithium-boro-tellurite glass. Both blue (⁴F_9/2→⁶H_15/2) and yellow (⁴F_9/2→⁶H_13/2) emission bands have been obtained from Dy³⁺ glass. From the measured decay profiles, the lifetimes of the emissions of the Sm³⁺ glass (⁴G_5/2→⁶H_{5/2, 7/2, 9/2 and 11/2}) at an excitation of 401 nm have been found to be in the range 0.47–0.81 ms, and with respect to the Dy³⁺ emissions (⁴F_9/2→⁶H_{15/2 and 13/2}), with excitation at 450 nm, are measured to be in the range of 0.302–0.307 ms. Stimulated emission cross-sections (σ ^E _p ) of the measured emission transitions have also been computed and the values are in the range of (0.38–1.20) × 10⁻²⁰ cm² for Sm³⁺ and for Dy³⁺ doped lithium-boro-tellurite glass the values are (0.66–1.39) × 10⁻²⁰ cm².