2D materials

Definition

2D materials belong to a class of nanomaterials consisting of just a single or a few atomic layers. Within the layer, the atoms are joined by covalent bonds, while neighbouring layers are held together only by weak interactions. This allows individual layers to be isolated. The best-known variant is graphene, a 0.3 nanometre-thick single layer of carbon atoms obtained from graphite. As well as being the thinnest substance known to science, it is also the strongest. It is transparent or absorbent depending on the wavelength, polarisation and electrical polarity, and it is extremely conductive.

But graphene is just one example, since there are more than 6000 materials that are stable in two-dimensional form and consist of one or more elements. Their properties cover the entire spectrum of physical states, from insulating to semiconducting and magnetic to superconducting and metallic. In addition, layers of 2D materials, either of the same type or different, can be stacked to form heterostructures like a kind of “atomic Lego”. The resulting stack forms an artificial material with new properties and the potential to drive advances in miniaturisation as well as energy and resource efficiency.

Current applications and opportunities

In the automotive and aerospace sectors, graphene is used for coating or as an additive for plastics, which results in lightweight yet resilient materials. The biocompatibility of graphene and graphene-related materials enables applications in biomedicine, such as the production of neural implants with additional functions or the local administration of therapeutic agents. In current research, 2D materials are used in batteries as conductors, in insulators and catalysts as well as in optoelectronics, sensor technology and spintronics, combining conventional electronics with the quantum mechanical properties of electrons.

This type of material is rarely found in end products, as it is still at an early stage of technological maturity and the market potential is unclear. With ETH Zurich, EPFL and Empa, Switzerland has three institutions from the ETH Domain that conduct world-class research into 2D materials. Successful transfer of this knowledge to industry will bring opportunities for Switzerland on the components market and as a supplier of special elements such as high-speed photodiodes.

Challenges

Despite major advances in the synthesis and production of 2D materials, the leap from the lab to industry is still to be made. One of the reasons is the scaling of the processes: On a laboratory scale, high-quality materials can be obtained in a method that essentially involves simple adhesive tape, but the production of large-scale layers remains a challenge at present. For graphene, there are now several companies that offer single- and multi-layer wafers of this material. Solving the problem of scalability for a far greater number of materials requires not only materials research, but also technology transfer to industry. Industrial adaptation is expected to progress rapidly owing to the potential of 2D materials.

Producing 2D materials and processing them into components requires cleanrooms that start-ups and even established companies cannot afford at the outset. One solution is for the state to provide initial funding for a fabrication laboratory – or FabLab for short – for semiconductors that can be used by universities and industry.

Although Switzerland conducts top-level research in a number of areas, the lack of networking among stakeholders at national level is a barrier to innovation. One way of pooling expertise could be through interdisciplinary programmes encompassing chemistry, electrical engineering, materials science, physics and quantum information science. This could be complemented by a technology transfer centre to promote dialogue between the realms of industry and research.

Focus on industry

There are opportunities for industry in the production and characterisation of a wide variety of 2D materials. Another business area is the manufacture of new components. Compared to traditional materials, 2D materials can be applied to almost all surfaces without high investment costs. This means that combined materials and components can be manufactured significantly more cheaply. In addition, 2D materials have unique properties that give them competitive advantages.

Unlocking the industrial potential of 2D materials will require the help of specialists in semiconductor and nanotechnology, chemistry, electrical engineering, materials science and applied physics. In Switzerland, more and more specialists have been trained in these areas in recent years.

International perspective

For the last few years, impetus and funding in the field of 2D materials have come mainly from the EU. The European Chips Act, which came into force in 2023, aims to establish core competencies and achieve partial autonomy in semiconductor production. If it wants to retain its competitive edge, Switzerland must strive to become part of this emerging ecosystem. In addition, EU funding is strongly geared towards collaboration with European partners and the corresponding companies, which is why few projects are implemented between universities and industry in Switzerland. National funding programmes could make up for this.

Future applications

2D materials can be produced with little effort and their properties can be manipulated by applying stresses, using adjacent layers or through other physical methods. This results in new, artificial materials with optimal physical and mechanical properties. This is not only of interest for basic research, but also opens the door to numerous industrial applications. In the semiconductor industry, 2D materials could replace silicon as a carrier material for transistors. As well as unlocking a new level of miniaturisation for transistors, this is also expected to lead to significant efficiency gains thanks to a new transistor architecture. Optically active heterostructures could revolutionise photovoltaics by enabling efficient absorption and energy conversion while using minimal amounts of material. This property also makes them potentially useful for optoelectronic circuits. Even though universities are currently driving development and most of the applications are only available on a laboratory scale, the pathway into industry is clear: Forecasts for the electronics, composites and batteries sectors expect sales of up to one billion US dollars in the coming years.

The potential of 2D materials is huge. Thanks to their unique physical and mechanical properties, they have the power to revolutionise the battery, electronics, semiconductor and photovoltaic industries as well as lightweight construction, and set new standards in biomedicine. Not only do they drive achievements in miniaturisation, they also promote the efficient use of energy and resources, which translates into more sustainable products. In order to exploit this potential, Switzerland needs start-up funding for cleanrooms and national, interdisciplinary programmes that link the worlds of science and industry and enable commercialisation.