Preparation of microflake ink for low cost printing of CIS-Se absorber layers

Mechanical alloying and bead milling techniques were used for the low cost preparation of precursor inks for printing CIS-Se absorber layers. The plate shaped microflake particle precursor is composed of nanostructured elemental Copper-Indium-Sulfur and Selenium. The high aspect ratio microflakes have a typical thickness around 200 nm and a diameter of 1-5 μm. The plate shape of the microflakes facilitates the deposition of a high quality film during the coating process. Moreover, the nanostructured nature of the microflakes improves the sintering behavior during selenization. The milling technique is relatively low cost, easily up-scalable, fast and very flexible in targeted composition.