Laser thinning to get a direct-bandgap semiconductor

Molybdenum disulphide is an indirect bandgap semiconductor in bulk, but a direct bandgap semiconductor as a single layer. Single-layer MoS2 could be used in a variety of optoelectronic and photoelectric applications, possibly as a cheaper replacement for graphene in certain applications. Previously the struggle has been reliably producing single sheets of MoS2. "Although mechanical and chemical exfoliation methods can be used to obtain high quality MoS2 single layers, the lack of control in the thickness, shape, size, and position of the flakes limits their usefulness." Instead, the paper describes a technique for reliably producing single-layer MoS2 with the ability to design and produce shapes down to 200nm using lasers.