“In 2016, annual global semiconductor sales reached their highest-ever point, at $339 billion worldwide. In that same year, the semiconductor industry spent about $7.2 billion worldwide on wafers that serve as the substrates for microelectronics components, which can be turned into transistors, light-emitting diodes, and other electronic and photonic devices. A new technique developed by MIT engineers may vastly reduce the overall cost of wafer technology and enable devices made from more exotic, higher-performing semiconductor materials than conventional silicon. The new method, reported today in Nature, uses graphene — single-atom-thin sheets of graphite — as a sort of “copy machine” to transfer intricate crystalline patterns from an underlying semiconductor wafer to a top layer of identical material. The engineers worked out carefully controlled procedures to place single sheets of graphene onto an expensive wafer. They then grew semiconducting material over the graphene layer. They found that graphene is thin enough to appear electrically invisible, allowing the top layer to see through the graphene to the underlying crystalline wafer, imprinting its patterns without being influenced by the graphene. Graphene is also rather “slippery” and does not tend to stick to other materials easily, enabling the engineers to simply peel the top semiconducting layer from the wafer after its structures have been imprinted.”