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The future of solar is nanotech: Nanogram, Sunflake and other upcoming technologies

With a fresh $32 million funding going to nanotechnoloy firm NanoGram, mainly for development of next-generation solar cells, it’s a good time to point out some up-and-coming technologies that work on very small scales to make photovoltaic cells more efficient.

NanoGram has already had several commercial successes, including inventions in both electronics and medicine. However, the company has of late turned its sights on boosting the efficiency of solar cells.

The company is working on ultra-thin crystalline silicon which it says will reduce the cost of silicon-based solar cells to below $1 per watt hour, a price point that is generally considered a breakthrough.

Its latest funding is notable because Nanogram had so far only taken $27 million in funding since its inception in 1996, growing to over $20 million in annual revenue. It plans to use the additional $32 million (investor details at bottom) in part toward a pilot plant for solar modules.

sunflake.JPGSunFlake A/S, a European company, makes the same claim of being able to manufacture a low-cost cell with about 30 percent efficiency, roughly double the efficiency of the average solar cell available today.

Headed by noted scientist Martin Aagesen, the company plans to make use of a type of nanowire discovered by Aagesen that he calls “nanoflakes.” Blessed with a perfect crystalline structure, nanoflakes are capable of absorbing nearly all light directed at them, according to the company.

By growing its nanowires into a low-grade silicon substrate, SunFlake will reduce the need for large amounts of high-quality polysilicon when making cells. However, it has yet to announce plans to commercially manufacture cells.

zhang.JPGAnother methods on the horizon is the use of metal oxide nanoparticals in cells. Dr. Jin Zhang of the University of California, Santa Cruz, plans to use a combination of nanoparticles and quantum dots (using nano-crystals, as SunFlake does) to make a highly efficient solar cell.

(Nanotechnology, by the way, refers the field of science that works at the atomic and molecular scale, roughly between 1 to 100 nanometers. Elements and compounds take on different characteristics when they are so tiny, and studying them is leading to new users and inventions, as we’re seeing here.)

A team led by Zhang and including other researchers from China and Mexico recently tested a prototype cell using a nanocomposite material of their own devising. The cell performed even better than the researchers expected.

“We’re manipulating the energy levels of the nanocomposite material so the electrons can work more efficiently for electricity generation,” Zhang told ScienceDaily. His research is currently supported by various governmental groups from the three countries involved.

One note when considering these up-and-coming technologies: It will probably be about five years before they hit the market in force. However, as new technologies become more common, existing cost balances between different solar technologies, like polysilicon and CIGS cells, will likely be upset.

Finally, returning to NanoGram’s funding, the company brought on new investors Global Cleantech Capital, Masdar Clean Tech Fund, Mitsui Ventures, Nagase & Company, Nanostart AG, TEL Venture Capital, and Yasuda Enterprise Development for the round. Existing investors ATA Ventures, Bay Partners, Harris & Harris, Institutional Venture Partners, Nth Power, Rockport Capital Partners, SBV Venture Partners, and Technology Partners also participated.