Solexant, a secretive solar cell developer in Sunnyvale, Calif, has raised $4.3 million in a first round of capital to develop a prototype of its technology.

The funding came to light in a regulatory filing, and chief executive Damoder Reddy tells VentureBeat he didn’t want to provide many details.

X/Seed Capital led the round, which included Firelake Capital, Medley Partners and Trident Capital. The company earlier raised a seed round, and will like look for a second round next year when it is ready to start making its photovoltaic cells.

Elsewhere, Solexant is described as developing “high efficiency low-cost nanostructured solar cells. Solexant solar cells achieve high efficiency by incorporating nanomaterials that harvest light from the entire solar spectrum and achieve low cost by adopting roll to roll manufacturing process. Solexant IR nanostructures can be integrated into thin film solar cells to increase efficiency and reduce cost. Solexant business model is to make/sell broadband nanostructured solar cells to OEMs and make/sell IR absorbing nanomaterials and nanostructures to thin film solar cell manufacturers.”

Additionally, VentureWire (subscription required) cites a patent application by Reddy:

The Solexant application describes an electroluminescent device and touts the advantages of using nanomaterials called quantum dots. “The next generation emissive display technology is expected to be based on newly emerging nanomaterials called quantum dots,” the patent filing states. “Emission in these displays is from inorganic materials such as CdSe, which are inherently more stable than OLED materials.” Reddy’s previous venture was Nuelight Corp., a semiconductor company he founded. It develops OLED display devices to improve flat panel displays in such consumer objects as smart phones, portable DVD players, laptop monitors and televisions.