Scientists at Rice University and the Oak Ridge National Laboratory (ORNL) recently raised the possibility of using monoatomic thickness semiconductor materials to fabricate a new generation of electronic components; the team found that they could improve the production of molybdenum disulfide (mo) in chemical vapor deposition (CVD) furnaces by deliberately introducing defects on substrates. Lybdenum disulphide is a monolayer.

The team also pointed out that adding the newly developed process to their previous research and development on the combination of graphene and hexagonal boron nitride materials would enhance the possibility of making custom crystals and optimize the fabrication of such crystals as field-effect transistors, integrated logic circuits, photodetectors (MDS) and soft optoelectronic components.

Scientists have been studying the properties of two-dimensional electron gas (2-D electron gas) between the interfaces of two different materials for many years. Graphene, i.e., carbon arranged in a hexagonal monoatomic layer mode, exhibits excellent electron mobility, thermal conductivity and strength, but graphene, an excellent conductor, is not the only material that can exhibit a hexagonal monoatomic layer arrangement. There are also molybdenum disulfide, which belongs to semiconductors, and hexagonal boron nitride (hBN), which is an insulator.

Members include Jun Lou, Pulickel Ajayan and Boris Yakobson, professors of mechanical engineering and materials science at Rice University, and Wu Zhou, academician and researcher Juan-Carlos Idrobo, academician of Oak Ridge National Laboratory, who are trying to combine the above three materials to build 2D electronic components; the team has previously completed the combination of graphene and hexagonal boron nitride, but molybdenum disulfide grows. It is not easy. The fine grains produced by early CVD experiments are not practical.

"Molybdenum disulfide does not nucleate as easily as hBN and graphene," said Sina Najmaei, a graduate student at Rice University who also participated in the study. "We are beginning to find that artificial edges can be added to the substrate to control nucleation, and now the material has a better growth effect between such structures. "

Lou, a professor at Rice University, said: "Now we can grow crystalline particles about 100 microns in diameter. Although they are thinner than human hair, they are large enough in the nano world. "