Schottky barrier tuning in semiconducting ZnO and BaTiO₃ hybrid heterostructures shows dielectric and electrical anisotropy

Abstract

Polygonal nanosize BaTiO3 and modified BaTiO3 with carbon are prepared using a modified hydrothermal process and utilized as solutes to set up bimodal hollow zinc oxide (ZnO) heterostructures.

Exploring the Carrier Dynamics in Zinc Oxide–Metal Halide-Based Perovskite Nanostructures: Toward Reduced Dielectric Loss and Improved Photocurrent

“…However, both the samples showed enhanced dielectric polarization and strong frequency dependence at lower frequencies (<10 4 Hz), which are due to hopping of electrons/holes caused by the Maxwell−Wagner−Sillars (MWS) effect and named space charge/interfacial polarization; thereafter, they showed a slow decrease at higher frequencies, which is due to dominant orientation polarization. 58,61,62 Here in at higher frequencies the dipoles do not have much time to polarize and lag behind the applied electric field, as a result decrease in dielectric permittivity was observed. On the other hand, Figure 6B shows the dielectric loss tangent (tan δ) with respect to frequency for both the systems.…”

Intrinsic asymmetric ferroelectricity induced giant electroresistance in ZnO/BaTiO3 superlattice

“…Here, the thickness of ZnO/BaTiO 3 superlattice is less than 4 nm, which is thinner than those currently available in experiment. [18][19][20][21][22] Essentially speaking, the asymmetric ferroelectricity of ZnO/ BaTiO 3 superlattice comes from the relative orientations of polarizations of ZnO and BaTiO 3 in supercells. When the orientations of the polarization of ZnO and BaTiO 3 are opposite, the counteraction of the intensity of total polarization is appeared.…”

“…[14][15][16][17] Coupling between the piezoelectric ZnO and the ferroelectric BaTiO 3 may cause bistable ferroelectric polarization orientation. [18][19][20][21][22] The piezoelectric ZnO has an inherent polarization which is difficult to reverse using an electric eld, but the polarization of ferroelectric BaTiO 3 can be reversed in experiments. The parallel or antiparallel polarizations of ZnO and BaTiO 3 may lead to intrinsic asymmetric ferroelectricity in the ZnO/BaTiO 3 superlattice which is similar to that found in tricolor superlattices.…”

Polarization-Induced Quantum-Mechanical Charge Transfer in Perovskite–Graphene Nanocomposites with Superior Electro-optic Switching Modulation

“…Furthermore, these physical phenomena of dielectric polarization and relaxation behavior were studied in the frequencies of 0.1 Hz to 1 MHz, to explore the significant contribution and influence of the E-O sensitivity of the device. Previously, the broad-band dielectric/impedance spectroscopic studies have been carried out on various nanostructured/nanocomposite materials to validate the significant contribution of the bulk electrical behavior on the device performance. − To date, very few reports are available about the dielectric properties of inorganic/organic perovskite-based nanostructures and their E-O studies. − Moreover, the direct correlation between polarization-induced E-O sensitivity and charge-transfer dynamics was rarely discussed in the graphene–metal halide perovskite nanocomposites. In these composite halide perovskites, multiple dielectric mechanisms (such as ionic, dipolar/orientational, and space charge/interfacial) are contributed by the frequency-dependent applied electric potential, which causes distortion in the spatial distribution of charges and provides dielectric polarization …”