Semiconducting 2-D alloys could be key to overcoming the technical limitations of modern electronics. Although 2-D Si–Ge alloys would have interesting properties for this purpose, they were only predicted theoretically. Now, scientists from Japan Advanced Institute of Science and Technology have realized the first experimental demonstration. They have also shown that the Si to Ge ratio can be adjusted to fine tune the electronic properties of the alloys, paving the way for novel applications.