In April of this year, the Swiss research institution "Empa", headed by Prof. Dr. Ayodhya Tiwari, announced a more cost-effective and environmentally friendly production method for transparently conductive coatings in the ETH Domain. How they are used as so-called TCO's in tablets, laptops, smartphones, flat screens and solar cells.

So far, TCO (= Transparent Conductive Oxides), which consists of a mixture of indium and tin oxide, has mainly been used in the electrical industry. However, indium has a high demand and a correspondingly high price due to increasing scarcity of raw materials. For this reason, the inexpensive variant, zinc oxide mixed with aluminum, is being used more and more frequently. This is usually applied to a substrate in a high vacuum by means of plasma sputtering, which makes the manufacturing process energy-intensive, complex and also expensive. Empa researchers in the "Thin Films and Photovoltaics" department have now developed a water-based method that is used to apply a TCO layer of aluminum and zinc salts to a substrate without a vacuum.

The last production step, the curing of the TCO layer, is due to the water-based method that less energy is required than before. According to members of the research team, more heat-sensitive substrates (e.g. flexible plastics) can also be used because the substrate is no longer heated to 400 - 600 degrees as before, but only to 90 degrees.

We are not the only ones who think that the research results sound interesting. According to the EMPA Research Institute, interested parties from industry are already involved. So work is already underway to establish Empa's TCO on a large scale. If you would like to learn more about this, you can read the full report from the Swiss-based research institute at the URL in our reference.