In the world of semiconductors, impurities and defects can be a good thing. They modify the properties of materials such as silicon, and scientists can exploit these properties to develop better transistors for laptops, smart phones, and solar cells.
Recently, a new class of semiconductor was discovered that is only three atoms thick and which extends in a two-dimensional plane, similar to graphene. These 2-D semiconductors, called Transition Metal Dichalcogenides (TMDs), have exceptional optical characteristics. They can be developed into ultra-sensitive photo detectors, and a single TMD layer emits as much light as a 3-D TMD crystal composed of 10,000 layers.
For the past several years, scientists have wondered if impurities and defects could also modify TMDs' intrinsic properties, perhaps in ways that improve the semiconductor or lead to new functionalities.
Scientists from the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley have taken a big step toward answering this question. As recently reported in the journal Nature Physics, they found -- to their surprise -- how substantial linear defects in TMDs create entirely new properties. Some of these properties indicate that defects in TMDs might even mediate superconducting states.
To read more, click here.