Study finds diamonds can conduct electricity like metals

Scientists at NTU Singapore, the Massachusetts Institute of Technology (MIT), US, and the Skolkovo Institute of Science and Technology (Skoltech), Russia, has shown as an early proof-of-concept that mechanical strain applied to nanoscale diamond needles could reversibly alter their geometry and hence their electrical properties, giving them a metal-like conductivity at room temperature and pressure.

The study published in the journal Proceedings of the National Academy of Sciences of the United States of America on 5 October 2020, could lead to future applications in power electronics used in a wide variety of machines from cars and electrical appliances to smart grids;  highly efficient light emitting diodes (LEDs); optical devices; and quantum sensing, which enhances and improves what sensors can currently do.

This finding follows an experimental discovery by an NTU-Hong Kong-MIT team of scientists led by NTU Singapore President Professor Subra Suresh, who reported in a 2018 paper published in Science that diamond nano-needles – each about a thousand times thinner than a strand of human hair – can be bent and stretched substantially, so that they snap back without being damaged when the strain is released.

Prof Suresh, who is also NTU Distinguished University Professor, said: “The ability to engineer and design electrical conductivity in diamond without changing its chemical composition and stability offers unprecedented flexibility to custom-design its functions.  The methods demonstrated in this work could be applied to a broad range of other semi-conductor materials of technological interest in mechanical, microelectronics, biomedical, energy and photonics applications, through strain engineering.”