One of the challenges of producing thin film solar panels lies in the materials used. Unlike rigid polycrystalline modules and monocrystalline solar panels that utilise silicon, a commonly occurring substance, thin film solar cells incorporate copper indium gallium selenide or cadmium telluride.
Indium, gallium and cadmium are very costly due to scarcity and cadmium is a heavy metal that potentially poses hazards to human health and the wider environment.
IBM announced last week it has constructed a thin film solar cell made entirely of readily-available elements and furthermore, says it has set a new world record for efficiency for thin film solar cells using the same materials.
Comprised of copper (Cu), tin (Sn), zinc (Zn), sulfur (S), and/or selenium (Se), the solar cells demonstrates a conversion efficiency of 9.6 percent, which the company says is 40 percent higher than the value previously achieved for this set of materials. The material class is known as kesterites, materials with a crystal structure very similar to that of chalcopyrites.
The solar cell was created using a combination of solution and nanoparticle-based approaches instead of the common and more expensive vacuum-based technique. IBM states that along with the cheaper materials, the different manufacturing process is expected to enable much lower fabrication costs, as it is consistent with high-throughput and high materials utilization based deposition techniques including printing, dip and spray coating and slit casting.
IBM says it does not plan to manufacture solar panels, but is open to partnering with solar cell manufacturers to demonstrate the technology.
