Engineering Directional Charge Carrier Transport Using Ferroelectric Polarization for Enhanced Photoelectrochemical Water Oxidation.

Introducing ferroelectric polarization has shown great potential to facilitate interfacial charge separation in photoelectrochemical (PEC) water splitting. However, unambiguous evidence of the actual influence of spontaneous ferroelectric polarization, as compared to heterojunction formation, on electron extraction and PEC water splitting is still lacking to date. Herein, core-shell BaTiO3/TiO nanostructures are designed as photoanodes based on paraelectric cubic and ferroelectric tetragonal phases BaTiO (BTO) perovskite.

Structure and Transport Properties of the BiCuSeO-BiCuSO Solid Solution.

In this paper, we report on the crystal structure and the electrical and thermal transport properties of the BiCuSeSO series. From the evolution of the structural parameters with the substitution rate, we can confidently conclude that a complete solid solution exists between the BiCuSeO and BiCuSO end members, without any miscibility gap. However, the decrease of the stability of the materials when increasing the sulfur fraction, with a simultaneous volatilization, makes it difficult to obtain S-rich samples in a single phase.

Invited article: A round robin test of the uncertainty on the measurement of the thermoelectric dimensionless figure of merit of Co0.97Ni0.03Sb3.

A round robin test aiming at measuring the high-temperature thermoelectric properties was carried out by a group of European (mainly French) laboratories (labs). Polycrystalline skutterudite Co0.97Ni0.

BaCu2Se2 based compounds as promising thermoelectric materials.

In the past few years, many studies have been devoted to the thermoelectric properties of copper selenides and sulfides, and several families of materials have been developed with promising performances. In this paper, we report on the synthesis and thermoelectric properties of Na-doped BaCu2Se2 from 20 K to 773 K. By Na doping at the Ba site, the electrical conductivity can be increased by 2 orders of magnitude, and the power factor can reach 8.

High thermoelectric properties of n-type AgBiSe2.

We report on the thermoelectric (TE) performance of intrinsic n-type AgBiSe2, a Pb-free material with more earth-abundant and cheaper elements than intrinsic p-type homologous AgSbTe2. Pb doping changes n-type AgBiSe2 to p-type but leads to poor electrical transport properties. Nb doping enhances the TE properties of n-type AgBiSe2 by increasing the carrier concentration.

Evidence of a structural phase transition in superconducting SmFeAsO(1-x)F(x) from 19F NMR.

We report resistivity, magnetization and (19)F NMR results in a polycrystalline sample of SmFeAsO(0.86)F(0.14).

Remarkable enhancement in thermoelectric performance of BiCuSeO by Cu deficiencies.

A significant enhancement of thermoelectric performance in layered oxyselenides BiCuSeO was achieved. The electrical conductivity and Seebeck coefficient of BiCu(1-x)SeO (x = 0-0.1) indicate that the carriers were introduced in the (Cu(2)Se(2))(2-) layer by Cu deficiencies.

Effects of Co doping on the transport properties and superconductivity in CeFe(1-x)Co(x)AsO.

A series of CeFe(1-x)Co(x)AsO oxyarsenide compounds with Co doping on iron sites (x = 0-0.2) have been synthesized by a solid state reaction method. The effects of Co doping on the electrical transport properties and superconductivity were analyzed with a special emphasis on the analysis of thermopower.