Thin film manufacturer Miasolé has broken its own record for CIGS efficiency, achieving 20.56% with a CIGS solar cell deposited on a stainless steel foil substrate.
The device measured 0.86cm² and was produced on Miasolé’s pilot production line in California. Recently, the company set a new record for a flexible large area CIGS module at 17.44%. The company says its latest achievement is the result of improvements to the process, noting that the equivalent mini cell efficiency for the large area module is 19.8%.
According to Miasolé, the cell was produced using processes that are directly transferable to high volume manufacturing. Company CTO Atiye Bayman told pv magazine that Miasolé does its development on the production line, and that mini cells such as this are important to show improvements at the diode level, to the junction or absorber layer.
Bayman goes on to explain that scaling up from 0.86 cm² to a full size 136cm² cell, would likely mean a 1-1.5% efficiency loss due to non-uniformity and micro shunting, with another loss of around 0.5% coming from cell to module. He also notes that third party measurements include light stabilization, which can further impact the efficiency by 1-2%, and is not the case for mini cell measurements.
Miasolé reports that current, light stabilized efficiency from its pilot production line in California is 17.1%, while its factory in China, which runs an older version of the recipe, has an average production efficiency of 16.2%.