Imec at PVSEC in Valencia, Spain – September 6-10, 2010

In 2009, imec launched an industrial affiliation program (IIAP) on crystalline Si PV. As with imec’s other successful IIAPs in IC scaling, imec defined the generic base for the research: developing technologies to reduce the cost of energy production through silicon solar cells. Companies are invited to join imec’s Si PV IIAP to do joint precompetitive research. By bringing companies together around this program, imec aims to create an ecosystem with solar cell producers, material suppliers, tool suppliers, and energy companies. The cross-fertilization between these will advance the research to new levels. The multi-partner R&D initiative has already generated a lot of interest from industrial players. Important players such as Schott Solar, Total, GDF Suez and Photovoltech ... joined the Si PV IIAP already last year.

At PVSEC, imec will report in a news release advances in its Si PV program including advanced emitter processes.

Other results that will be highlighted:

Record efficiencies for large-area epitaxial thin-film silicon solar cells
Imec realized large-area (70cm2) epitaxial solar cells with efficiencies of up to 16.3% on high-quality substrates. And efficiencies of up to 14.7% were achieved on low-quality substrates showing the potential of thin-film epitaxial solar cells for industrial manufacturing. The results were achieved within imec’s silicon solar cell industrial affiliation program (IIAP) that explores and develops advanced process technologies aiming a sharp reduction in silicon use, whilst increasing cell efficiency and hence further lowering substantially the cost per Watt peak.
These efficiencies of up to 16.3% on high-quality substrates and of up to14.7 % on low-cost substrates show that industrial-level efficiencies are within reach for this technology;” said Jef Poortmans, director imec energy/solar program. “By implementing copper-based contact schemes, we can further increase the efficiency making epitaxial thin-film silicon solar cells on low-cost wafers an interesting industrial technology.

Increased efficiencies in tandem organic solar cells
A further increase of the efficiency is essential to make organic solar cells a viable alternative to silicon solar cells. Stacking active layers in a tandem configuration results in an increase in the absorption spectrum and concurrently and efficiency improvement. Imec optimized its tandem structure resulting in stacked organic solar cells that yield higher efficiency than for the separate cells. To our knowledge, the reported efficiency in such a configuration is the best ever reported.

Significant reduction of the cost of germanium-based thermophotovoltaic (TPV) cells
Regarding imec TPV research, imec developed an improved processing technique for germanium-based thermophotovoltaic (TPV) cells resulting in significant reduction of cell cost, an essential step to develop a market for thermophotovoltaic applications. Imec’s newly developed TPV cells are fabricated on germanium substrates with a rough surface, instead of the traditionally used substrates with expensive mirror-polished front surfaces.