Dual-junction PV cells fabricated

RF Micro Devices (RFMD) (www.rfmd.com) recently announced that it has fabricated dual-junction photovoltaic (PV) cells that integrate gallium arsenide (GaAs) and indium gallium phosphide (InGaP) PV junctions using the company’s standard 6-in. semiconductor equipment. The successful fabrication of the dual-junction PV cells promises the development of triple-junction structures, with the ultimate goal of developing a commercially viable and high-volume-capable compound semiconductor-based process for high-performance PV cells.

The announcement is the fruit of the company’s 2009 cooperative agreement with the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) to develop a production-capable process technology for high-performance PV cells. NREL has decades of research experience in PV cell technology.

The dual-junction achievement and associated performance characteristics are consistent with results achieved by NREL in its development of Inverted Metamorphic Multi-Junction (IMM) technology. NREL’s technology has demonstrated one of the world’s highest reported solar cell conversion efficiencies, at 40.8%, and continued substantial improvements in efficiency are anticipated.

This dual-junction development was achieved using the firm’s manufacturing capabilities and robust supply chain, which are optimized for high volume, low cost, reliability, and performance. The conversion efficiency achieved across its 6-in. wafers was exceptionally uniform, enabling high device yields and tight distributions in CPV product performance. The company’s development efforts regarding a compound semiconductor-based process for PV cells are applicable across a broad range of technologies, including IMM as well as conventional triple-junction Germanium-based CPV devices. The firm expects many opportunities related to PV cells and is engaged with CPV system integrators and solar cell module manufacturers.

Christina Nickolas