Experiments in magnet lab reveal secrets of very promising semi conductor

Sacha Oleksandr Zheliuk

Researchers at HFML-FELIX have – in collaboration with scientists from Groningen and Singapore – made some important discoveries on a new and very promising semi conductor.

Through the years, electronics have become smaller and smaller and because of this, researchers are now starting to be confronted with the limits of physics. Electronic processes beyond this limit can indeed work very differently, sometimes causing devices to stop working all together.

That is why scientists are looking for other options. For example: new two-dimensional electronic systems, made of materials that are not yet on the market. Materials that are being built in the lab at a nano-level and that – with the right stimuli – show characteristics we haven’t seen before. Super conductivity for instance, or magnetism.

Promising materials

Examples of such new and promising materials are graphene (rewarded with a Nobel prize in 2010), black phosphorus and 2D-TMDs (two-dimensional transition metal dichalcogenides). Consisting of only one or a few atom layers, they show amazing optical, electrical, chemical and mechanical characteristics. That makes them interesting candidates for a number of applications, like sensors, catalyst and quantum electronics.

In the past couple of years two-dimensional oxides have caught the interest of scientists as well. These are chemical compounds with at least one oxygen atom. One of the rising stars in this category is bismuth oxyselenide (Bi2O2Se). But to work with this new material, we first have to fully understand it and so far, we have not.

Quantum Hall Effect

In a recent publication in Nature Communications researchers at HFML-FELIX, in collaborations with scientists from Groningen and Singapore, have now revealed some of the secrets of Bi2O2Se. In particular, they have been able to make high-quality electronic devices and have shown the Quantum Hall Effect (known for Nobel prizes in 1985, 1998 and 2010) in this interesting material.

The Quantum Hall Effect describes how to very precisely and universally measure electronic resistance in materials with a thickness of only a few atoms. By studying this effect in high magnetic fields and at low temperatures – exactly what they have done with Bi2O2Se in this study – scientist can say more about the fundamental characteristics of new materials. Only then do they become interesting for future applications like quantum electronics.

You can find the new paper on the Nature website:

Quantum Hall effect in a CVD-grown oxide

Contact information:
oleksandr.zheliuk@ru.nl