New material for flat semiconductors


Researchers find a two-dimensional, self-assembling material that might produce solar cells or transistors.

Researchers around the world have been working to harness the unusual properties of graphene, a two-dimensional sheet of carbon atoms. But graphene lacks one important characteristic that would make it even more useful: a property called a bandgap, which is essential for making devices such as computer chips and solar cells.

Now, researchers at MIT and Harvard University have found a two-dimensional material whose properties are very similar to graphene, but with some distinct advantages — including the fact that this material naturally has a usable bandgap.

The research, just published online in the Journal of the American Chemical Society, was carried out by MIT assistant professor of chemistry Mircea Dincă and seven co-authors.

The new material, a combination of nickel and an organic compound called HITP, also has the advantage of self-assembly: Its constituents naturally assemble themselves, a “bottom-up” approach that could lend itself to easier manufacturing and tuning of desired properties by adjusting relative amounts of the ingredients.

Research on such two-dimensional materials, which often possess extraordinary properties, is “all the rage these days, and for good reason,” Dincă says. Graphene, for example, has extremely good electrical and thermal conductivity, as well as great strength. But its lack of a bandgap forces researchers to modify it for certain uses — such as by adding other molecules that attach themselves to its structure — measures that tend to degrade the properties that made the material desirable in the first place.

The new compound, Ni3(HITP)2, shares graphene’s perfectly hexagonal honeycomb structure. What’s more, multiple layers of the material naturally form perfectly aligned stacks, with the openings at the centers of the hexagons all of precisely the same size, about 2 nanometers (billionths of a meter) across.

In these initial experiments, the researchers studied the material in bulk form, rather than as flat sheets; Dincă says that makes the current results — including excellent electrical conductivity — even more impressive, since these properties should be better yet in a 2-D version of the material. “There’s every reason to believe that the properties of the particles are worse than those of a sheet,” he says, “but they’re still impressive.”

What’s more, this is just the first of what could be a diverse family of similar materials built from different metals or organic compounds. “Now we have an entire arsenal of organic synthesis and inorganic synthesis,” Dincă says, that could be harnessed to “tune the properties, with atom-like precision and virtually infinite tunability.”

Such materials, Dincă says, might ultimately lend themselves to solar cells whose ability to capture different wavelengths of light could be matched to the solar spectrum, or to improved supercapacitors, which can store electrical energy until it’s needed.

In addition, the new material could lend itself to use in basic research on the properties of matter, or to the creation of exotic materials such as magnetic topological insulators, or materials that exhibit quantum Hall effects. “They’re in the same class of materials that have been predicted to have exotic new electronic states,” Dincă says. “These would be the first examples of these effects in materials made out of organic molecules. People are excited about that.”

Pingyun Feng, a professor of chemistry at the University of California at Riverside who was not involved in this work, says the approach used by this team is “novel and surprising,” and that “the quality of this work, from the synthetic design strategy to the probing of the structural details and to the discovery of exceptional electrical conductivity, is outstanding.” She adds that this finding “represents a major advance in the synthetic design of novel semiconducting materials.”


12 Responses to New material for flat semiconductors

  1. M.A Legodi May 4, 2014 at 12:03 pm #

    Wow. All thanks to science. All thanks to the new compound that is of more value than graphene
    . I
    believe this will bring solution to the world energy resources across the world.

  2. Justine 14077142 May 4, 2014 at 6:30 am #

    From the get-go I questioned my physics and maths teachers, always asking, ‘Are we really going to need this after school? What is the point of learning this? I’ve never seen anyone use this in the real world.’ Little did I know, Maths and Physics forms a part of everything. We might not always see the intricacy of it, but there is no doubt about it that it is indeed there. Whether it be a structure of a building or the programming of a computer, it is everywhere. This blog here is a perfect example of it. By altering the structure of Ni3(HITP)2 to a flatter 2D shape researchers were able to determine the best structure to allow conductible properties to be present. Well done to the researcher who made this breakthrough in science.

  3. Neo(13122381) May 3, 2014 at 12:38 pm #

    its amazing how sciences simplify our lives

  4. Maropeng(u13236998) May 3, 2014 at 3:29 am #

    It is so amazing how all the science findings can come up to the knowledge of informing many people what the constituent of all the things their lives revolve around are. wow what an interesting article.

  5. u14007739 May 3, 2014 at 12:38 am #

    There is only one word to say NANOTECHNOLOGY, all thanks to the great findings of Physicist Richard Feynman. I bet that he didn’t count on his work gaining so much momentum in a short period of time. New compounds and materials are being produced everynow and then, compounds that have a great deal properties that makes them desirable and essential for their application. Imagine a simlple mixture of a metal and an organic compound that can produce a useful complex material that can conduct electricity but not heat for resistance, that can change colour when stretched and is flexable enough to perform all sorts of activities.

  6. Thembeka Mabena (14111536) May 2, 2014 at 9:57 am #

    great article

  7. Jordan Kouskos May 1, 2014 at 3:30 am #

    The newly discovered compound lends itself to be able to enhance the current use of solar energy in that it will be able to capture more form of light energy allowing for more viable and possibly better uses of solar and light energy. The new compound is exciting in the world of science and could possibly be incredibly helpful to the energy crisis the world is going through. This excites me as this could lead to the end of load shedding and possibly be able to provide better and more viable electricity to rural areas. 14088241

  8. Matthew(14104131) May 1, 2014 at 2:57 am #

    This is a fantastic discovery which can be extremely beneficial to all communities around the world. The clear advantages which Ni3(HITP)2 will help many areas of the world with energy problems. This new 2D compound is a major break through in the scientific field and could open many doors for other research such as in sports equipment or various ways of alternate energy sources. I am very interested to follow the development of the new compound and to see its benefits it shows to society.

  9. Kegomoditswe (14094500) April 30, 2014 at 12:54 pm #

    There is no doubt that indeed this lies among the most incredible researches ever undertaken by mankind. What is intriguing about it is the two-fold ability it entails, to bring about the highly desired characteristics of graphene whilst eliminating its least liked ones.

    Seemingly the unleashed Ni3(HITP)2 compound will help find missing links in many other researches undertaken concerning semiconductors and discovery of a handful of other intriguing ideas.

  10. u14004454 April 30, 2014 at 10:44 am #

    I am very exited about the unlimited possibilities for this type of material. I agree with Charissa and Matt, the semi-conductive properties of this material means it can be used to a great advantage and, that the material might even help solve some of our energy crises. The fact that this material keeps all of the advantages of graphite and has advantages that scientist wished graphite had just amazes me. I can only imagine the possibilities other materials,mixtures of organic substances and elements, like Ni3(HITP)2, can provide.

  11. Matt Burgerhoff (14011248) April 30, 2014 at 9:19 am #

    I totally agree with Charissa. There are countless uses for semiconductors and lots of research is being carried out about them. The new compound sounds like it could be super efficient and cost effective. It has got all the advantages of Graphene minus the unwanted disadvantages.

    I am interested to see how this research goes. It can open so many doors and make multiple ideas that were once too costly possible.

    Could this new compound be the solution to our global energy crisis?

  12. Charissa (14277761) April 30, 2014 at 6:51 am #

    This sounds like a very interesting discovery. Semicondutors have a wide use in the technology that we use every day. There has obviously been a lot of research put into graphene, but it does have a disadvantage in its lack of bandgap. This new compound sounds very interesting in the way that it overcomes graphene’s disadvantage while maintaining all of its advantages. It will be interesting to follow the development of the research and how useful the compound actually turns out to be. Solar energy is also very important at this time when we have to try and find alternative energy sources. New compounds with properties such as this one might make solar energy a viable alternative in the near future.

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