TL;DR: Pb-layered perovskite (benzylammonium)2PbCl4 is ferroelectric with semiconducting behaviours, and this finding throws light on the new properties of the hybrid organo-plumbate or stannate compounds and provides a new way to develop new semiconductor ferroelectrics.
Abstract: Inorganic semiconductor ferroelectrics such as BiFeO3 have shown great potential in photovoltaic and other applications. Currently, semiconducting properties and the corresponding application in optoelectronic devices of hybrid organo-plumbate or stannate are a hot topic of academic research; more and more of such hybrids have been synthesized. Structurally, these hybrids are suitable for exploration of ferroelectricity. Therefore, the design of molecular ferroelectric semiconductors based on these hybrids provides a possibility to obtain new or high-performance semiconductor ferroelectrics. Here we investigated Pb-layered perovskites, and found the layer perovskite (benzylammonium)2PbCl4 is ferroelectric with semiconducting behaviours. It has a larger ferroelectric spontaneous polarization Ps=13 μC cm(-2) and a higher Curie temperature Tc=438 K with a band gap of 3.65 eV. This finding throws light on the new properties of the hybrid organo-plumbate or stannate compounds and provides a new way to develop new semiconductor ferroelectrics.
TL;DR: The participation of the normally inert A- site cation in the electronic structure near the Fermi level can be considered an inductive effect, as it utilizes substitution on the A-site to directly modify the electronic structures of the SnO(3)(2)(-) framework.
Abstract: Experimental and computational studies were performed to understand the electronic structure of ternary perovskites (ASnO3, A = Ca, Sr, Ba, Cd), pyrochlores (RE2Sn2O7, RE = Y, La, Lu; Cd2Sb2O7), and defect pyrochlore oxides (Ag2Sb2O6) containing the main group ions Sn4+ and Sb5+. In all compounds, the lowest energy states in the conduction band arise primarily from the antibonding Sn/Sb 5s−O 2p interaction. In the alkaline-earth stannate perovskites (BaSnO3, SrSnO3, and CaSnO3) the conduction bandwidth decreases strongly in response to the octahedral tilting distortion triggered by the decreasing size of the alkaline-earth cation. This in turn leads to a corresponding increase in the band gap from 3.1 eV in BaSnO3 to 4.4 eV in CaSnO3. The band gap of CdSnO3 is relatively small (3.0 eV) considering the large octahedral tilting distortion. The origin of this apparent anomaly is the mixing between the empty Cd 5s orbitals and the antibonding Sn 5s−O 2p states. This mixing leads to a widening of the conductio...
TL;DR: The bulk of developmental work on transparent conducting oxides (TCOs) has been somewhat empirical as discussed by the authors, which applies both to more familiar materials such as indium tin oxide (ITO) and to less-well-known materials that have emerged in recent years.
Abstract: The bulk of developmental work on transparent conducting oxides (TCOs) has been somewhat empirical. This statement applies both to more familiar materials such as indium tin oxide (ITO) and to less-well-known materials that have emerged in recent years. In this article, we place a greater emphasis on more fundamental research. Our eventual goal is to gain a thorough understanding of these materials, their potential for further improvement, whether or not they suggest new and potentially superior materials, and the way their properties are influenced by structural and other issues. We also hope to provide guidelines to other researchers working in this area. We have investigated films of cadmium oxide (CdO), cadmium stannate (Cd2SnO4 or CTO), and zinc stannate [Zn2SnO4 (ZTO)]. The CdO was prepared by chemical-vapor deposition, whereas the stannates were prepared by rf sputtering. In both cases, Corning 7059 glass substrates were used. However, some depositions were also made onto tin oxide, which had a pro...
TL;DR: In this paper, single-phase spinel zinc stannate (Zn2SnO4) thin films were grown by rf magnetron sputtering onto glass substrates.
Abstract: Single-phase, spinel zinc stannate (Zn2SnO4) thin films were grown by rf magnetron sputtering onto glass substrates. Uniaxially oriented films with resistivities of 10−2–10−3 Ω cm, mobilities of 16–26 cm2/V s, and n-type carrier concentrations in the low 1019 cm−3 range were achieved. X-ray diffraction peak intensity studies established the films to be in the inverse spinel configuration. 119Sn Mossbauer studies identified two octahedral Sn sites, each with a unique quadrupole splitting, but with a common isomer shift consistent with Sn+4. A pronounced Burstein–Moss shift moved the optical band gap from 3.35 to as high as 3.89 eV. Density-of-states effective mass, relaxation time, mobility, Fermi energy level, and a scattering parameter were calculated from resistivity, Hall, Seebeck, and Nernst coefficient transport data. Effective-mass values increased with carrier concentration from 0.16 to 0.26 me as the Fermi energy increased from 0.2 to 0.9 eV above the conduction-band minimum. A bottom-of-the-band ...
TL;DR: In this article, the electric field induced phase transition behavior of lead lanthanum zirconate titanate stannate (PLZTS) ceramics was investigated.
Abstract: The electric field induced phase transition behavior of lead lanthanum zirconate titanate stannate (PLZTS) ceramics was investigated. PLZTS undergoes a tetragonal antiferroelectric (AFETet) to rhombohedral ferroelectric (FERh) phase transition with the application of an electric field. The volume increase associated with this antiferroelectric (AFE)–ferroelectric (FE) phase transition plays an important role with respect to actuator applications. This volume increase involves an increase in both transverse and longitudinal strains. The E field at which the transverse strain increases is accompanied by an abrupt jump in polarization. The longitudinal strain, however, lags behind this polarization jump exhibiting a slight decrease at the onset of phase switching. This decoupling was related to the preferentially oriented AFE domain configuration, with its tetragonal c-axis perpendicular to the applied electric field. It is suggested that phase switching involves multiple steps involving both structural tran...