R. Paul Brooker

Effects of Silicotungstic Acid Addition to the Electrodes of Polymer Electrolyte Membrane Fuel Cells

Operation of polymer electrolyte membrane fuel cells at elevated temperatures and low relative humidity is limited by the electrolytes dependence on water. The addition of a heteropolyacid, specifically silicotungstic acid (STA), is shown to increase the activity of platinum for the oxygen reduction reaction by nearly 73% at 118°C/40% relative humidity. However, STA-containing electrodes have a significantly higher diffusion resistance, countering any activity improvement at higher currents. By reducing the electrode ionomer weight fraction, the diffusion resistance decreases. Also, membrane durability is improved significantly by including STA at the cathode.

Correlating wafer surface to DW saw profile and wire wear

The surface of diamond-wire sawn wafers is investigated as a function of different wires. The evolution of the pilgrim waves on the wafer surface is correlated with wire movement. Analysis of wafer surfaces indicated that some wires generate lower surface roughness than others, even using the same sawing recipe.

A review of manufacturing metrology for improved reliability of silicon photovoltaic modules

In this work, the use of manufacturing metrology across the supply chain to improve crystalline silicon (c-Si) photovoltaic (PV) module reliability and durability is addressed. Additionally, an overview and summary of a recent extensive literature survey of relevant measurement techniques aimed at reducing or eliminating the probability of field failures is presented. An assessment of potential gaps is also given, wherein the PV community could benefit from new research and demonstration efforts. This review is divided into three primary areas representing different parts of the c-Si PV supply chain: (1) feedstock production, crystallization and wafering; (2) cell manufacturing; and (3) module manufacturing.