E-Mail IMAGE: Researchers at Linköping University, Sweden, have developed a stable high-conductivity polymer ink. The new n-type material comes in the form of ink with ethanol as the solvent.... view more Credit: Thor Balkhed Researchers at Linköping University, Sweden, have developed a stable high-conductivity polymer ink. The advance paves the way for innovative printed electronics with high energy efficiency. The results have been published in Nature Communications. Electrically conducting polymers have made possible the development of flexible and lightweight electronic components such as organic biosensors, solar cells, light-emitting diodes, transistors, and batteries. The electrical properties of the conducting polymers can be tuned using a method known as "doping". In this method, various dopant molecules are added to the polymer to change its properties. Depending on the dopant, the doped polymer can conduct electricity by the motion of either negatively charged electrons (an "n-type" conductor), or positively charged holes (a "p-type" conductor). Today, the most commonly used conducting polymer is the p-type conductor PEDOT:PSS. PEDOT:PSS has several compelling features such as high electrical conductivity, excellent ambient stability, and most importantly, commercial availability as an aqueous dispersion. However, many electronic devices require a combination of p-types and n-types to function. At the moment, there is no n-type equivalent to PEDOT:PSS.