The semiconductors in Stion’s thin-film solar panels are made of Copper, Indium, Gallium, Selenium and Sulfur (a compound commonly abbreviated as CIGS). Traditionally, CIGS-based materials have demonstrated the highest efficiencies of any thin-film technology. However, there are many variations of the technology and performance varies widely based on how the materials are deposited and processed. CIGS semiconductor film is comprised of both metallic and non-metallic elements. Stion employs two separate process steps to form the semiconductor film. The first is ideally suited for deposition of metallic elements. The second is ideal to supply and incorporate non-metallic elements in the film. These two processes enable exceptional large area uniformity.

The first step, sputtering (physical vapor deposition), is a high volume industrial process in which a metal source “target” is bombarded with energized particles, dislodging metal atoms which the coat the glass surface with a thin metal.

In the second step, the coated glass is placed in a large furnace and heated together with selenium and sulfur gasses to convert the sputtered metal layer into the CIGS semiconductor.

By combining these common materials with propietary science, Stion is able to make extremely efficient thin film solar panels. Although only a few grams of each of these materials are used to make a panel, they play a pivotal role in solar electricity generation. Fortunately, these materials are also plentiful byproducts of some of the most commonly mined metals in the world. Each year millions of tons of Zinc, Aluminum and Copper are refined and as a small part of this process, the Indium, Gallium and Selenium that Stion uses is extracted.

By combining these common materials with the power of the sun, Stion makes technically superior and incredibly affordable solar panels.