Photoelectrochemical (PEC) water splitting for hydrogen production is a promising technology that uses sunlight and water to produce renewable hydrogen with oxygen as a by-product. In the expanding field of PEC hydrogen production, the use of standardized screening methods and reporting has emerged as a necessity. This article is intended to provide guidance on key practices in characterization of PEC materials and proper reporting of efficiencies. Presented here are the definitions of various efficiency values that pertain to PEC, with an emphasis on the importance of solar-to-hydrogen efficiency, as well as a flow chart with standard procedures for PEC characterization techniques for planar photoelectrode materials (i.e., not suspensions of particles) with a focus on single band gap absorbers. These guidelines serve as a foundation and prelude to a much more complete and in-depth discussion of PEC techniques and procedures presented elsewhere.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0884291400005653

Accelerating materials development for photoelectrochemical hydrogen production: Standards for methods, definitions, and reporting protocols

Nanotechnology has opened new and exhilarating opportunities for exploring glucose biosensing applications of the newly prepared nanostructured materials. Nanostructured metal-oxides have been extensively explored to develop biosensors with high sensitivity, fast response times, and stability for the determination of glucose by electrochemical oxidation. This article concentrates mainly on the development of different nanostructured metal-oxide [such as ZnO, Cu(I)/(II) oxides, MnO2, TiO2, CeO2, SiO2, ZrO2, and other metal-oxides] based glucose biosensors. Additionally, we devote our attention to the operating principles (i.e., potentiometric, amperometric, impedimetric and conductometric) of these nanostructured metal-oxide based glucose sensors. Finally, this review concludes with a personal prospective and some challenges of these nanoscaled sensors.

/pdf/a-comprehensive-review-of-glucose-biosensors-based-on-ye0vz5ywv7.pdf

A comprehensive review of glucose biosensors based on nanostructured metal-oxides.

Preparation of copper oxide thin film by the sol-gel-like dip technique and study of their structural and optical properties

Films of copper(I) oxide can be electrodeposited by reduction of copper(II) lactate in alkaline solution. Rietveld analysis of electrochemically grown films reveals pure copper(I) oxide with no copper(II) oxide or copper metal present in the films and a lattice parameter of a = 0.4266 nm. The cathodic deposition current is limited by a Schottky-like barrier that forms between the Cu2O and the deposition solution. A barrier height of 0.6 eV was determined from the exponential dependence of the deposition current on the solution temperature. At a solution pH of 9 the orientation of the film is [100], while at a solution pH of 12 the orientation changes to [111]. Atomic force images of the [100] oriented films have crystals shaped as four-sided pyramids, while the [111] films have triangular crystals. The grain size for films grown at 65 °C ranges from 2 to 5 μm. A refractive index of 2.6 was measured from the transmission spectrum for wavelengths between 1350 and 2800 nm. The p-type semiconductor has a dire...

/pdf/electrochemical-deposition-of-copper-i-oxide-films-3kcgjeaszk.pdf

Electrochemical Deposition of Copper(I) Oxide Films

Transparent conducting oxides constitute a unique class of materials combining properties of electrical conductivity and optical transparency in a single material. They are needed for a wide range of applications including solar cells, flat panel displays, touch screens, light emitting diodes and transparent electronics. Most of the commercially available TCOs are n-type, such as Sn doped In2O3, Al doped ZnO, and F doped SnO2. However, the development of efficient p-type TCOs remains an outstanding challenge. This challenge is thought to be due to the localized nature of the O 2p derived valence band which leads to difficulty in introducing shallow acceptors and large hole effective masses. In 1997 Hosono and co-workers (1997 Nature 389 939) proposed the concept of 'chemical modulation of the valence band' to mitigate this problem using hybridization of O 2p orbitals with close-shell Cu 3d (10) orbitals. This work has sparked tremendous interest in designing p-TCO materials together with deep understanding the underlying materials physics. In this article, we will provide a comprehensive review on traditional and recently emergent p-TCOs, including Cu(+)-based delafossites, layered oxychalcogenides, nd (6) spinel oxides, Cr(3+)-based oxides (3d (3)) and post-transition metal oxides with lone pair state (ns (2)). We will focus our discussions on the basic materials physics of these materials in terms of electronic structures, doping and defect properties for p-type conductivity and optical properties. Device applications based on p-TCOs for transparent p-n junctions will also be briefly discussed.

/pdf/p-type-transparent-conducting-oxides-xctaxvxjef.pdf

P-type transparent conducting oxides.

Electrodeposition and characterization of cuprous oxide

Space-charge-limited Schottky diodes are fabricated by evaporation of gold on electrodeposited CdTe films. The charge transport mechanisms, in both polarities, are studied. Thermionic emission and space-charge-limited conduction theories can adequately describe the transport properties. The latter mechanism is controlled by a donor-type deep level whose ionization energy varies with the applied voltage according to the Poole-Frenkel effect. Bardeen's model in which the Fermi level is pinned to the interface states, can explain the voltage dependence of the barrier height in these devices. Some of the important parameters of CdTe films are measured from the characteristics of these diodes.

Charge transport mechanisms in Au-CdTe space-charge-limited Schottky diodes

Potentiostatic electrodeposition of cuprous oxide

A novel approach is used, for the first time, for the determination of both thickness (d) and refractive index (n) of Cu2O thin film using thermal and optical interferometry techniques. This approach results in more reliable values of these two parameters than the values obtained by using conventional spectroscopic techniques. This approach can also be extended to obtain the values of d and n for other thin films.



Ein neues Verfahren wird erstmalig benutzt, um sowohl die Dicke (d) als auch den Brechungsindex (n) von dunnen Cu2O-Schichten mittels thermischer und optischer Interferometrie zu bestimmen. Dieses Verfahren ergibt zuverlassigere Werte fur diese beiden Parameter als die ublichen spektroskopischen Methoden. Das Verfahren kann auch auf die Bestimmung der Werte fur d und n fur andere dunne Schichten ausgedehnt werden.

A. E. Rakhshani

Papers

Electrodeposition and characterization of cuprous oxide

Charge transport mechanisms in Au-CdTe space-charge-limited Schottky diodes

Potentiostatic electrodeposition of cuprous oxide

Determination of the Thickness and Refractive Index of Cu2O Thin Film Using Thermal and Optical Interferometry

Deep energy levels and photoelectrical properties of thin cuprous oxide films