The new cell architecture (above) developed at the David Ben-Gurion National Solar Research Center at Ben-Gurion University of the Negev can exceed an ultra-efficient 40 percent conversion efficiency with intensities equal to 10,000 suns. When irradiated from the side, it generates solar conversion efficiencies that rival, and may eventually surpass, the most ultra-efficient photovolataics.
This diagram is a schematic drawing of a 3-tier 6-terminal MBVJ solar cell. The number of tiers/materials is a design variable, and both the width (sub-cell dimension along the x-axis) and depth (sub-cell dimension along the z-axis) of each vertical junction need to be optimized. Credit: Ben-Gurion University of the Negev Researchers at Ben-Gurion University of the Negev (BGU) have developed a radically new design for a concentrator solar cell that, when irradiated from the side, generates solar conversion efficiencies which rival, and may eventually surpass, the most ultra-efficient photovoltaics.
Read more at: http://phys.org/news/2012-11-team-side-illuminated-ultra-efficient-solar-cell.html#jCp