24-Sep-2019 - Japan Science and Technology Agency

Clarification of a new synthesis mechanism of semiconductor atomic sheet

Toward the realization of next-generation flexible optoelectronic devices

In Japan Science and Technology Agency's Strategic Basic Research Programs, Associate Professor Toshiaki Kato and Professor Toshiro Kaneko of the Department of Electronic Engineering, Graduate School of Engineering, Tohoku University succeeded in clarifying a new synthesis mechanism regarding transition metal dichalcogenides (TMD), which are semiconductor atomic sheets having thickness in atomic order.

Because it is difficult to directly observe the aspect of the growing process of TMD in a special environment, the initial growth process remained unclear, and it has been desirable to elucidate a detailed mechanism of synthesis to obtain high-quality TMD.

An in-situ observing synthesis method has been developed by our research group to examine the growth aspect of TMD as a real-time optical image in a special high temperature atmosphere of about 800°C in the presence of corrosive gases. In addition, a synthesis substrate, which is a mechanism to control diffusion during the crystal growth of a precursor, has been developed in advance; further, it has been clarified that the growing precursor diffuses a distance about 100 times larger than in conventional semiconductor materials. It was also demonstrated that nucleation occurs due to the involvement of the precursor in a droplet state. Furthermore, by utilizing this method, a large-scale integration of more than 35,000 monolayer single crystal atomic sheets has been achieved on a substrate in a practical scale.

Utilizing the results of the present research, the large-scale integration of atomic-order thick semiconductor atomic sheets can be fabricated and is expected to be put into practical use in the field of next-generation flexible electronics.

Facts, background information, dossiers
More about Japan Science and Technology Agency
More about Tohoku University
  • News

    Simple, mass production of giant vesicles using a porous silicone material

    A technique to generate large amounts of giant vesicle (liposome) dispersion has been developed. The technique involves adsorbing a lipid into a silicone porous material resembling a "marshmallow-like gel" and then squeezing it out like a sponge by impregnating a buffer solution. This work ... more

    Efficient synthesis of multi-substituted anilines by domino rearrangement

    Anilines have been widely used in medicine, in particular in acetaminophen pain killers. They are also used in organic materials, such as liquid crystals and organic light-emitting diodes. The ability to efficiently synthesize a new class of aniline derivatives will enable further developme ... more

    Stacking on the graphene

    Researchers in Japan have found a way to form two materials, each made of three layers of graphene. Each material's graphene is stacked differently and has unique electrical properties. Their work has implications for the development of novel electronic devices, such as photo sensors that c ... more

  • Videos

    Shape Memory Alloy Demonstration

    The Mg-Sc alloy sheet was changed into a round shape using liquid nitrogen. The sheet was then exposed to ambient air. It returned to its original shape upon heating. more