The Oxygen Evolution Reaction Drives Passivity Breakdown for Ni-Cr-Mo Alloys.

Corrosion is the main factor limiting the lifetime of metallic materials, and a fundamental understanding of the governing mechanism and surface processes is difficult to achieve since the thin oxide films at the metal-liquid interface governing passivity are notoriously challenging to study. In this work, a combination of synchrotron-based techniques and electrochemical methods is used to investigate the passive film breakdown of a Ni-Cr-Mo alloy, which is used in many industrial applications. This alloy is found to be active toward oxygen evolution reaction (OER), and the OER onset coincides with the loss of passivity and severe metal dissolution.

Measuring Incompatibility and Clustering Quantum Observables with a Quantum Switch.

The existence of incompatible observables is a cornerstone of quantum mechanics and a valuable resource in quantum technologies. Here we introduce a measure of incompatibility, called the mutual eigenspace disturbance (MED), which quantifies the amount of disturbance induced by the measurement of a sharp observable on the eigenspaces of another. The MED provides a metric on the space of von Neumann measurements, and can be efficiently estimated by letting the measurement processes act in an indefinite order, using a setup known as the quantum switch, which also allows one to quantify the noncommutativity of arbitrary quantum processes.

Atomic Layer Grown Zinc-Tin Oxide as an Alternative Buffer Layer for CuZnSnS-Based Thin Film Solar Cells: Influence of Absorber Surface Treatment on Buffer Layer Growth.

Zn Sn O (ZTO) deposited by atomic layer deposition has shown promising results as a buffer layer material for kesterite CuZnSnS (CZTS) thin film solar cells. Increased performance was observed when a ZTO buffer layer was used as compared to the traditional CdS buffer, and the performance was further increased after an air annealing treatment of the absorber. In this work, we study how CZTS absorber surface treatments may influence the chemical and electronic properties at the ZTO/CZTS interface and the reactions that may occur at the absorber surface prior to atomic layer deposition of the buffer layer.

Surface/Interface Effects by Alkali Postdeposition Treatments of (Ag,Cu)(In,Ga)Se Thin Film Solar Cells.

Ag alloying and the introduction of alkali elements through a postdeposition treatment are two approaches to improve the performance of Cu(In,Ga)Se (CIGS) thin film solar cells. In particular, a postdeposition treatment of an alkali metal fluoride of the absorber has shown a beneficial effect on the solar cells performance due to an increase in the open circuit voltage ( ) for both (Ag,Cu)(In,Ga)Se (ACIGS) and CIGS based solar cells. Several reasons have been suggested for the improved in CIGS solar cells including absorber surface and interface effects.

Sensitivity of Nitrogen K-Edge X-ray Absorption to Halide Substitution and Thermal Fluctuations in Methylammonium Lead-Halide Perovskites.

The performance of hybrid perovskite materials in solar cells crucially depends on their electronic properties, and it is important to investigate contributions to the total electronic structure from specific components in the material. In a combined theoretical and experimental study of CHNHPbI-methylammonium lead triiodide (MAPI)-and its bromide cousin CHNHPbBr (MAPB), we analyze nitrogen K-edge (N 1s-to-2p*) X-ray absorption (XA) spectra measured in MAPI and MAPB single crystals. This permits comparison of spectral features to the local character of unoccupied molecular orbitals on the CHNH (MA) counterions and allows us to investigate how thermal fluctuations, hydrogen bonding, and halide-ion substitution influence the XA spectra as a measure of the local electronic structure.