High performance monolayer tungsten disulfide

       

  Since the first two-dimensional material graphene was found in experiments, two-dimensional electronic materials have been studied for decades. Graphene and similar two-dimensional materials are only one atomic thickness, and is called a single layer of materials, their thickness is smaller than the thickness of a paper hundreds of times. These two-dimensional materials have great advantages and potential, that is, high flexibility, strength and conductivity, but they are used in practical or very challenging.

  Graphene (monolayer carbon atoms) has been studied in the field of transistors for a long time, but its lack of bandgap brings difficulties to semiconductor applications. Shahrjerdi explains: "You can not turn off the graphene transistor." Unlike graphene, tungsten disulfide has a considerable bandgap, and it also shows new properties: when the number of atoms is increased, Is tunable and can absorb and emit light strongly at the thickness of a single atomic layer, making it ideal for optoelectronics, sensing and flexible electronics.

  Efforts for the development of single-layer materials tend to be affected by defects in the material itself, and impurities and structural disorders can affect the mobility of carriers in semiconductors. Shahrjerdi and his students succeeded in reducing structural disorders by removing the growth promoter and using nitrogen instead of argon as the carrier gas.