Is Graphene the New Silicon?

Silicon has long been touted as a wonder material and is the raw material used in semiconductors. However, various challenges associated with it has pushed the industry to look for a replacement. Graphene has been identified as a suitable candidate for the fabrication of next-generation semiconductors, but immediate and quick adoption is not possible due to its shortcomings. However, with innovation and investment, graphene can be utilized to develop new and improved devices and applications.

The semiconductor was a revolutionary find that changed the electronic devices and automobile industries. By rapidly processing a large amount of data and downsizing computing technology, it helped to make electronic devices more sleek, sophisticated, and smart. The main material used in semiconductors is silicon.

Silicon is available in abundance and easily affordable. It can be used to both prevent and allow the flow of electricity and insulates. Innovation in the silicon industry has allowed semiconductor chips to become smaller and smarter. However, the industry is facing increased difficulty in extracting more value out of silicon. In addition, the mining and manufacturing of silicon damages the environment and causes ecological imbalance. Pure silicon must be fabricated artificially, which results in the emission of carbon monoxide into the atmosphere and adds to air pollution. This has led to the search for a more suitable candidate to replace this material.

One of the best finds in this search is graphene. It was discovered by two researchers, Andre Geim and Kostya Novoselov, at the University of Manchester in 2004. Graphene has the potential to become the next-generation semiconductor material owing to the exceptional properties that make it such a popular candidate, e.g., high mobility (~250x more than silicon), flexibility, low loss requirements, and small scale.

Challenges
However, complete replacement of silicon will take time as there are still challenges in graphene usage:

• Band gap engineering – Without a band gap, the graphene switch cannot be turned off. Researchers are still trying to find a solution to this problem.
• Graphene fabrication – The fabrication of graphene should generate quality crystals that are compatible with the current complementary metal-oxide semiconductor devices.
• Investments – A huge capital infusion will be required to set up fabs to enable usage of graphene. However, companies are implementing fab improvement plans to meet existing demand.
• Value chain – A completely new integrated value chain and supply chain for graphene would have to be created, which will again require large capital infusion.

Phased Implementation
Therefore, the replacement of silicon by graphene will occur but in phases.

• Phase 1 – In the first phase, graphene will be used as a silicon enhancer, which will improve the performance of various devices. For instance, it will lead to a longer transistor lifetime, better CPUs and memory, and enable niche applications such as radiofrequency analog.
• Phase 2 – In the second phase, once the key issues of graphene are solved, the initiation of silicon replacement will begin. It will be a transformational change that will lead to improvement in feature size and development of next-generation CPUs and memory.
• Phase 3 – In the last phase (expected after 25 years), graphene will be the main material used in semiconductors. Novel devices will be developed based on the principles of quantum computing or theory of spintronics. The next-generation devices will further lead to new and undiscovered applications.

Future of Graphene
Due to its remarkable properties, graphene has endless possibilities that can revolutionize the world.

• Graphene can be used to develop high-power batteries that would be fully charged within a few minutes.
• Its unique molecular composition makes graphene one of the smallest and most useful filters, which could be used to convert sea water into drinking water.
• Ongoing research on graphene is leading to experiments for new-age electronics that can be integrated with human biological systems. Hence, graphene gadgets can be implanted in the human body, allowing it to read the nervous system or talk to cells.
• Graphene is a much better material for use in bulletproof vests as it is both thin and strong.
• A new graphene contact lens has been developed that allows that wearer to see the complete infrared spectrum as well as UV light.

There are certain quality issues and production limitations of graphene that must be resolved to encourage wider adoption. As the world slowly becomes more environment-conscious, graphene will become a desirable material as it can make applications and production greener. For example, GrapheneCR is a manufacturing unit that uses a carbon-negative process to produce graphene from biochar. Similarly, another graphene producer, Universal Matter, uses a “flash” graphene process that transforms all forms of carbon-based waste into graphene.

Hence, graphene will soon become a mainstream material that will generate considerable demand and be an essential raw material in electronic devices.