Nanotechnology: A Treasure Trove With 1000 New 2D Materials

2D materials, which consist of a few layers of atoms, may well be the future of nanotechnology. They offer potential new applications and could be used in small, higher-performance and more energy-efficient devices. 2D materials were first discovered almost 15 years ago, but only a few dozen of them have been synthesized so far. Now, thanks to an approach developed by researchers from EPFL‘s Theory and Simulation of Materials Laboratory (THEOS) and from NCCR-MARVEL for Computational Design and Discovey of Novel Materials, many more promising 2D materials may now be identified. Their work was recently published in the journal Nature Nanotechnology, and even got a mention on the cover page.

The first 2D material to be isolated was graphene, in 2004, earning the researchers who discovered it a Nobel Prize in 2010. This marked the start of a whole new era in electronics, as graphene is light, transparent and resilient and, above all, a good conductor of electricity. It paved the way to new applications in numerous fields such as photovoltaics and optoelectronics.

A team from EPFL (Ecole Polytechnique Fédérale de Lausanne) and NCCR Marvel in Switzerland has identified more than 1,000 materials with a particularly interesting 2D structure. Their research, which made the cover page of Nature Nanotechnology, paves the way for groundbreaking technological applications.

To find other materials with similar properties, we focused on the feasibility of exfoliation,” explains Nicolas Mounet, a researcher in the THEOS lab and lead author of the study. “But instead of placing adhesive strips on graphite to see if the layers peeled off, like the Nobel Prize winners did, we used a digital method.”


How To Print Solar Cells Massively

Flexible optoelectronic devices that can be produced roll-to-roll – much like newspapers are printed – are a highly promising path to cheaper devices such as solar cells and LED lighting panels. Scientists from “TREASORES” European project present prototype flexible solar cell modules as well as novel silver-based transparent electrodes that outperform currently used materials.

printes solar cells
A flexible organic solar cell from TREASORES project undergoing mechanical testing: the cell is repeatedly flexed to a 25 mm radius whilst monitoring its performance. Such cells have shown lifetimes in excess of 4000 hours

In order to make solar energy widely affordable scientists and engineers all over the world are looking for low-cost production technologies. Flexible organic solar cells have a huge potential in this regard because they require only a minimum amount of (rather cheap) materials and can be manufactured in large quantities by roll-to-roll (R2R) processing. This requires, however, that the transparent electrodes, the barrier layers and even the entire devices be flexible. With these «ultra-flat» electrodes record efficiencies of up to 7% were obtained for organic solar cells using commercially available materials for light harvesting.