Putting an end to cracked screens

Most parts of a smartphone are made of silicon and other compounds, which are expensive and break easily; manufacturers are thus on the lookout for something more durable and less costly. Now an international team of scientists is working together to bring an end to cracked smartphone and tablet screens.

Dr Elton Santos, from Queen’s University Belfast, has been working with scientists from Stanford University, the University of California, Berkeley, California State University and Japan’s National Institute for Materials Science to create dynamic hybrid devices that are able to conduct electricity at unprecedented speeds and are light, durable and easy to manufacture in large-scale semiconductor plants. Their study has been published in the journal ACS Nano.

The team found that by combining semiconducting molecules C60 with layered materials, such as graphene and hBN, they produce a material which could revolutionise smart devices. The combination works because hBN provides stability, electronic compatibility and isolation charge to graphene, while C60 can transform sunlight into electricity. Any smart device made from this combination would benefit from this mix of features, which do not exist in materials naturally.

“Our findings show that this new ‘miracle material’ has similar physical properties to silicon but it has improved chemical stability, lightness and flexibility, which could potentially be used in smart devices and would be much less likely to break,” said Dr Santos.

“The material also could mean that devices use less energy than before because of the device architecture, so could have improved battery life and less electric shocks.”

The project initially started from the simulation side, with Dr Santos predicting that the assembly of hBN, graphene and C60 could result in a solid with remarkable new physical and chemical properties. He then talked with his Californian collaborators about the findings.

“By bringing together scientists from across the globe with expertise in chemistry, physics and materials science, we were able to work together and use simulations to predict how all of the materials could function when combined — and ultimately how these could work to help solve everyday problems,” Dr Santos said.

“It is a sort of a dream project for a theoretician, since the accuracy achieved in the experiments remarkably matched what I predicted and this is not normally easy to find. The model made several assumptions that have proven to be completely right.”

One issue that still needs to be solved with the team’s current research is that graphene and the new material architecture is lacking a ‘band gap’, which is the key to the on-off switching operations performed by electronic devices. However, Dr Santos’s team is already looking at a potential solution in transition metal dichalcogenides (TMDs) — chemically stable materials that have large sources for production and band gaps that rival silicon.

“By using these findings we have now produced a template, but in future we hope to add an additional feature with TMDs,” Dr Santos said. “These are semiconductors which bypass the problem of the band gap, so we now have a real transistor on the horizon.”

Image credit: ©stock.adobe.com/au/badztua