Nanosolar's Copper Indium Gallium Diselenide (CIGS) thin film has comparable efficiencies to regular multicrystalline silicon cells. However, the cost per watt for CIGS will be about 1/5th that of regular solar cells, making it comparable in cost to grid generated power at under $2 per watt.
Instead of using expensive vacuum based thin-film deposition processes, Nanosolar developed a nanoparticle ink that enables them to use a much simpler and higher yield printing process for depositing the solar cell's semiconductor onto a low-cost foil substrate; using a continuous roll-to-roll printing process. This enables the production of high-power high-current panels with significantly lower costs.
Nanosolar has developed a proprietary ink that makes it possible to simply print the semiconductor of the solar cell. The homogeneous mix of nanoparticles in the ink ensures that the atomic ratios of the elements are correct wherever the ink is printed, even across large areas of deposition. This contrasts to vacuum deposition processes where the various materials sources have to be "atomically" synchronized.
Printing is simpler, faster and more cost efficient than other semiconductor techniques. Using a process that can work in plain air without the need of vacuum deposition enables Nanosolar to significantly cut the costs of manufacture.
A thin-film solar cell consists of an absorber layer (the semiconductor) sandwiched in between a top and a bottom electrode layer. The thin films of the Nanosolar cell are deposited directly onto a highly conductive copper foil electrode, which is not only much simpler than electrodes used on glass or stainless steel substrates, it can carry 5-10 times more current than other thin-film cells.
- Roll-to-roll processing
Rolls that are meters wide and kilometers long can be processed efficiently with high throughput in equipment with significantly lower capital cost than current wafer-based methods.
Nanosolar has over 180 patents issued, licensed, or pending regarding all critical aspects of nanostructured solar cell materials and relevant product and equipment designs.