Getting graphene to dance to your tune

25 April 2018

Professor Meike Stöhr of the Zernike Institute for Advanced Materials has big plans for graphene – well, two big plans actually – made possible by the Vici grant she was awarded this year. She is confident that one of these plans will deliver the goods. The other one is a little more ‘challenging’

Photo: Sylvia Germes

When the email announcing the result of the Vici procedure arrived, Meike Stöhr didn’t open it straight away. Together with a group of colleagues, she was conducting a series of experiments using the synchrotron at Grenoble, and she didn’t want to be distracted by any disappointments. The memory of her unsuccessful Vici proposal the previous year was still fresh in her mind. “Later on, in the privacy of my office, I opened the email. I had to read it several times to make sure it was true – this time I had got it!” Prof. Stöhr was now able to pursue a long-held dream. “This grant gives me the time and space I need to put together a really great team. With this kind of security, you can launch a much larger study.”

Meike Stöhr and her group are researching graphene, an impressively versatile, chicken-wire shaped molecule. She adds organic molecules – sometimes in combination with metal atoms – to tweak the properties of graphene. The goal of her Vici-funded research project is to convert graphene into a good semiconductor. “Graphene is a great material, but it lacks something known as a ‘band gap’. That is a property common to all semiconductors”, Prof. Stöhr explains. Semiconductors have numerous applications in electronics. Many research groups throughout the world are trying to insert a band gap into graphene. Meike Stöhr points out that “By adding organic molecules to graphene, we can change its electrical properties. We manipulate the material’s electrons, ‘telling’ them where they may or may not go.” The idea of using organic molecules to create a band gap in graphene has been around for ten years or so, but no one has yet managed to make it a practical reality. Prof. Stöhr is confident that she will succeed where others have failed. “Nothing is certain in science, but I do have a good feeling about this. Over the past five years, my group has developed an in-depth knowledge of graphene. We can now put that to good use.”

Meike Stöhr also plans to use her Vici money to fund another – more risky – study. “I’m confident we’ll see an effect, but I'm just not sure it will work the way we expect.” Her new and untested idea is to use metal atoms to apply spin to graphene. Spin gives electrons direction, so that the material could be used to store data. “Our initial experiments have shown that the metal atoms start to cluster together, which is not exactly ideal”, says Prof. Stöhr. She hopes to counteract this clustering effect by inserting grids of organic molecules and metals into the graphene. “My hope is that the spins will settle into these grids, and that this will prevent clustering.”

She doesn’t need the Vici to take the step to full professor, she already is one. “That process was expedited last year, thanks to NWO’s Aspasia programme.” Aspasia is an incentive programme to promote talented female scientists to the post of associate professor or professor. Prof. Stöhr says that “In an ideal world, of course, there would be no need for a programme like this. But, as things stand, we need this measure to actively improve the position of women. Otherwise, things will never change. From kindergarten onwards, boys and girls are treated differently. This phenomenon is deeply ingrained in our society.”

Source: NWO