Epiwafer foundry and substrate maker IQE plc of Cardiff, UK has developed epitaxial processes for producing high-efficiency, triple-junction concentrator photovoltaic (CPV) solar cells with comparable results on both 6 inch diameter germanium (Ge) and gallium arsenide (GaAs) substrates.

IQE has been supplying the global chip industry as a pure-play contract manufacturer for more than two decades and is established in GaAs-based epiwafer products for wireless applications including RF components for mobile phone handsets. The group, which has manufacturing sites across Europe (Cardiff, Milton Keynes and Bath in the UK), Asia (Singapore) and the USA (Bethlehem, PA and Somerset, NJ), has been working with key partners during the last two years to develop multi-junction solar technologies for the provision of large-scale renewable energy.

Increased wafer sizes are an essential step in ensuring the provision of high-quality and highly efficient solar power generation at the lowest possible cost, says IQE. Current CPV technology is based on 4"-diameter wafers, but IQE says that its new capability has demonstrated what is claimed to be unsurpassed performance and excellent uniformity across 6" (150mm) diameter wafers. Peak multi-sun device performance is the same for both types of substrate (Ge and GaAs) and approaches the best previously achieved on 4" substrates using the same process, the firm adds.

" Delivering 6" diameter wafers for CPV applications is an important milestone for IQE," says group CEO & president Dr Drew Nelson. "Our experience as the world leading outsource manufacturer of GaAs-based wafers has enabled us to develop the capability to produce multi-junction solar cells on both GaAs and Ge substrates with comparable results, fully scalable from our well-established 4" process in terms of performance, uniformity, and yield," he adds.

"Our 6" CPV wafer products have generated a great deal of interest at both the cell supplier and systems-supplier level, and have demonstrated excellent performance and uniformities on which we will continue to build," Nelson concludes.