Mechanistic studies of hydrogen transport through MO2C/V composite membranes

Composite membranes comprised of vanadium foils coated with molybdenum carbide catalyst layers were recently introduced as alternatives to palladium for high temperature separation of H2. Experiments using D2/H2 mixtures unambiguously show that the mechanism involves dissociation, proton transport, and subsequent recombination. Temperature-dependent measurements of H2 flux were performed on sets of membranes in which the thickness of both the V foil and the Mo2CMo2C layers were varied in order to provide insight into the underlying transport mechanisms. It is shown that hydrogen transport through the carbide itself can be limiting for catalyst layers >20 nm. At temperature

Mechanistic studies of hydrogen transport through MO2C/V composite membranes

Composite membranes comprised of vanadium foils coated with molybdenum carbide catalyst layers were recently introduced as alternatives to palladium for high temperature separation of H2. Experiments using D2/H2 mixtures unambiguously show that the mechanism involves dissociation, proton transport, and subsequent recombination. Temperature-dependent measurements of H2 flux were performed on sets of membranes in which the thickness of both the V foil and the Mo2CMo2C layers were varied in order to provide insight into the underlying transport mechanisms. It is shown that hydrogen transport through the carbide itself can be limiting for catalyst layers >20 nm. At temperature

Development of ZnTe as a back contact material for thin film cadmium telluride solar cells

This is an Open Access Article. It is published by Elsevier under the Creative Commons Attribution 4.0 Licence (CC BY). Full details of this licence are available at http://creativecommons.org/licenses/by/4.0/Cadmium telluride (CdTe) is high-efficiency commercialised thin film photovoltaic technology. However, developing a stable low-resistivity back contact to the CdTe solar cells is still an issue. High work function and low level of doping of this material don't allow to create an ohmic contact with metals directly. Copper is commonly used to lower the back contact barrier in CdTe solar cells, but an excessive amount of copper diffusing through the cell is harmful for the device performance and stability. In this work a copper-doped ZnTe (ZnTe:Cu) buffer layer was incorporated in between CdTe and gold metal contact by high-rate pulsed DC magnetron sputtering. The back contact was then activated by rapid thermal processing (RTP) resulting in spectacular improvement in key device performance indicators, open circuit voltage (VOC) and fill factor (FF)