Sunlight Photonics was formed in 2007 by a team of former Bell Labs and NASA scientists and engineers to address an identified need for high-performance PV solar cells and modules which could be manufactured at competitive cost for terrestrial and aerospace extraterrestrial markets. The focus is on thin-film PV devices and Cu-In-Ga-Se (CIGS) based materials in particular, which have a demonstrated record performance of 20% conversion efficiency for small test cells (NREL 2009). The main challenges in this space pertain to the scaling of CIGS processing and cell fabrication to a manufacturing scale, while maintaining high efficiencies at a competitive cost. These challenges have been effectively addressed by the Sunlight team and the company is pursuing a manufacturing path which utilizes its proprietary solutions. Adapting to the market dynamics and commoditization of rigid PV modules, Sunlight’s business focus has moved to emerging applications where the full advantages of its technology can be utilized.
Sunlight Photonics is developing Sunlight® TFM solar cells and modules, which will be high power density, flexible, stretchable & lightweight. These products can provide solutions across a wide range of markets and applications including:
Solar UAV Aerospace Defense Transportation Mobile Electronics
Sunlight has proprietary PV cell designs and processing technologies targeting the Cu-In-Ga-Se (CIGS) family of PV materials. These materials offer the highest performance for thin-film devices. The realization of this potential on a manufacturing scale however has been challenging however, largely due to processing complexity and uniformity limitations over large areas.
To date, commercial CIGS products are manufactured on a limited scale with the highest product efficiencies reported in the 15% range, but more typically available in the 10-12% range. Like most PV modules, CIGS products are typically rigid with glass substrates/cover plates even if the CIGS cells are produced on foil substrates. A few suppliers also provide “flexible” modules incorporating cells on foil substrates. Typically, these are also heavily packaged with polymeric materials, which considerably reduce their potential weight advantage. Very few manufacturers make CIGS cells on polymeric substrates which potentially have the highest weight advantage. Typically these exhibit lower performance than devices on glass or metal foil substrates due to lower accessible temperatures in processing.
Sunlight’s proprietary single-source, single-step processing approach enables CIGS film to be deposited with excellent uniformity over large areas, it also embodies a substantial simplification of the processing and is compatible with low temperature processing. These attributes are the basis of a highly manufacturable technology which can be executed at low-cost and support processing on a wider range of flexible substrates for advanced applications.
Furthermore, Sunlight’s proprietary TFM cell designs enable specialty cells with the highest performance, which are tunable to different solar irradiations and work efficiently in both direct and diffuse illumination.