There are three areas where nanotechnology can impact solar according to Lux Research. First is in new ways to manufacture solar cells using new materials, with the key drawback being the use of toxic materials. Second are new types of cells using nano materials, with the key challenge being low lifetimes. Third is in peripherals, such as anti-reflective coatings, improving absorption coefficients, etc. Lux Research expects the solar industry to reach $40 billion in 2010, with nanotech representing approximately 30% of the market.

BIPV Eliminates Installation Costs

HelioVolt, headquartered in Austin, Texas, is focused on the first area, the use of new materials. The company is developing second generation copper indium gallium diselenide (CIGS) solar modules for built-in PV (BIPV) applications. HelioVolt claims that solar is limited by installation costs which are as much as the cost of the module itself; $3.50 for the module and $3.00 for installation. The company has discovered a peculiar and spontaneous nano-restructuring (he said it, I didn’t) behavior of CIGS under certain conditions which it exploits in its FASST process.

Rechargeable Solar Cells with Nano Antennas

Solaris, headquartered in Providence, Rhode Island, is focused on the second area, the use of new materials and new methods. The company is developing dye sensitized solar cells with a cost target of $1.00 per watt, which it claims can be reduced to $0.60 per watt if manufactured overseas. The goal is that the consumer has an upfront cost to install solar cells of less than $5,000, down from the $20,000 or $30,000 currently required. Solaris cells have 11% efficiency but are rechargeable. “We are borrowing a concept from Sony, by recharging the cell to improve lifetime.” Solaris cells use a screen printing process to deposit a transparent layer of electrolyte, embedded in a titanium dioxide and glass matrix. The company claims that the architecture allows the cells (the electrolyte) to be flushed out or recharged, which takes 30 minutes, every six years. They are currently focused on reducing the thickness of the active layer to reduce electrical losses. They are also working on improving the light absorption (more light with less material) by using nano antennas—essentially an antenna on a core shell structure (gold particle surrounded by titanium dioxide shell).

Eikos is focused on the third area of peripherals. For those of you familiar with Eikos, their first applications are targeting replacement of indium tin oxide (ITO) in the display industry, but they are now also exploring the development of conductive coatings for solar cells. They want to replace ITO everywhere and claim that the world only has indium supply left for the next 10 years. Eikos is using carbon nanotubes in inks/pastes to coat a variety of surfaces and aims to replace other methodologies used to collect electricity.