Anomalous Frequency and Temperature Dependent Scattering in the Dilute Metallic Phase in Lightly Doped SrTiO_{3}.

The mechanism of superconductivity in materials with aborted ferroelectricity and its emergence out of a dilute metallic phase in systems like doped SrTiO_{3} is an outstanding issue in condensed matter physics. This dilute metal has anomalous properties that are both similar and different to those found in the normal state of other unconventional superconductors. For instance, T^{2} resistivity can be found at densities that are too small to allow current decay through electron-electron scattering.

Directed crystallization of a poly(3,4-ethylenedioxythiophene) film by an iron(III) dodecyl sulfate lamellar superstructure.

Poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), a successfully commercialized polymeric semiconductor material, has potential as a transparent electrode in flexible electronic devices, yet has insufficient conductivity. We present the synthesis, properties, and directed crystallization of the PEDOT:dodecyl sulfate (PEDOT:DS) film. Iron(III) dodecyl sulfate (Fe(DS)) multi-lamellar vesicles (MLVs), a new growth template, are used to synthesize and direct the growth of the PEDOT:DS film via vapor-phase polymerization of 3,4-ethylenedioxythiophene to form huge PEDOT:DS co-crystal domains within the MLV superstructure.

Engineering metal oxidation using epitaxial strain.

The oxides of platinum group metals are promising for future electronics and spintronics due to the delicate interplay of spin-orbit coupling and electron correlation energies. However, their synthesis as thin films remains challenging due to their low vapour pressures and low oxidation potentials. Here we show how epitaxial strain can be used as a control knob to enhance metal oxidation.

Epitaxial SrTiO films with dielectric constants exceeding 25,000.

SignificanceSemiconductor interfaces are among the most important in use in modern technology. The properties they exhibit can either enable or disable the characteristics of the materials they connect for functional performance. While much is known about important junctions involving conventional semiconductors such as Si and GaAs, there are several unsolved mysteries surrounding interfaces between oxide semiconductors.

Anomalous transport in high-mobility superconducting SrTiO thin films.

The study of subtle effects on transport in semiconductors requires high-quality epitaxial structures with low defect density. Using hybrid molecular beam epitaxy (MBE), SrTiO films with a low-temperature mobility exceeding 42,000 cm V s at a low carrier density of 3 × 10 cm were achieved. A sudden and sharp decrease in residual resistivity accompanied by an enhancement in the superconducting transition temperature were observed across the second Lifshitz transition where the third band becomes occupied, revealing dominant intraband scattering.

Octahedral Symmetry Modification Induced Orbital Occupancy Variation in VO.

Octahedral symmetry is one of the parameters to tune the functional properties of complex oxides. VO, a complex oxide with a 3 electronic system, exhibits an insulator-metal transition (IMT) near room temperature (∼68 °C), accompanying a change in the octahedral structure from asymmetrical to symmetrical. However, the role of octahedral symmetry in VO on the IMT characteristics is unclear.

Nitrogen-Plasma-Treated Continuous Monolayer MoS for Improving Hydrogen Evolution Reaction.

Theoretically, the edges of a MoS flake and S-vacancy within the lattice have nearly zero Gibbs free energy for hydrogen adsorption, which is essentially correlated to the exchange currents in hydrogen evolution reaction (HER). However, MoS possesses insufficient active sites (edges and S-vacancies) in pristine form. Interestingly, active sites can be effectively engineered within the continuous MoS sheets by treating it with plasma in a controlled manner.

Investigation on energy bandgap states of amorphous SiZnSnO thin films.

The variation in energy bandgaps of amorphous oxide semiconducting SiZnSnO (a-SZTO) has been investigated by controlling the oxygen partial pressure (O). The systematic change in O during deposition has been used to control the electrical characteristics and energy bandgap of a-SZTO. As O increased, the electrical properties degraded, while the energy bandgap increased systematically.

Ultrasonic-Assisted Spin-Coating: Improved Junction by Enhanced Permeation of a Coating Material within Nanostructures.

Over the last decades, the spin-coating (SC) technique has been widely used to prepare thin films of various materials in the liquid phase on arbitrary substrates. The technique simply relies on the centrifugal force to spread a coating solution radially outward over the substrate. This mechanism works fairly well for solutions with low surface tension to form thin films of reasonable junctions on smooth substrates.