Researchers from Tokyo Metropolitan University have developed a way to produce high quality monolayers of a selection of different transition metal dichalcogenides which meet over an atomically thin seam. By coating this layer with an ion gel, a mixture of an ionic liquid and a polymer, they could excite light emission along the seam. The light was also found to be naturally circularly polarized, a product of the customizable strain across the boundary. Their results are published in Advanced Functional Materials