Flat-band systems in two-dimensional materials have recently attracted considerable interest due to their unique properties. However, the difficulties in electrically detecting the flat-band position in field-effect structures are slowing down the investigation of their properties. In this work, we use indium selenide (InSe) as a flat-band system due to a van Hove singularity at the valence-band edge in a few-layer form of the material without the requirement of a twist angle. We investigate tunneling photocurrents in gated few-layer InSe structures and relate them to ambipolar transport and photoluminescence measurements. We observe an appearance of a sharp change in tunneling mechanisms due to the presence of the van Hove singularity at the flat band. We further corroborate our findings by studying tunneling currents as a reliable probe for the flat-band position up to room temperature. Our results create an alternative approach to studying flat-band systems in heterostructures of two-dimensional materials. This could lead to the development of new optoelectronic devices based on flat-band systems.
Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory and Columbia University have made a significant breakthrough in the field of carbon capture and storage. They have developed a method to convert carbon dioxide (CO2), a potent greenhouse gas, into carbon nanofibers, materials with a wide range of unique properties and many potential […]
A new graphene sensor can detect COVID-19 and flu in 10 seconds and could be used to test for other respiratory infections as well. The sensor is made of graphene, a single layer of carbon atoms that is highly sensitive to the presence of viruses. It works by binding to antibodies that are specific to […]
Researchers at Tampere University in Finland have discovered a new immune response mechanism specific to exposure to nanoparticles. This mechanism is common to multiple species, from humans to simpler creatures, and it suggests that different species have adapted over time to this type of exposure. The findings of this study, published in the journal Nature […]