Diamond is undoubtedly a kind of non-metallic material. It has extremely high hardness and good insulation and thermal conductivity. But researchers from MIT and Nanyang Tech have recently discovered a controllable way that nanodiamonds can be pulled up from insulators, semiconductors, and even conductivity to the level of highly conductive metals, and this change can be achieved without losing the diamond material. Under the premise of reversible.
It is said that although the research is in its early stages, it may greatly expand the application of diamond materials to new high-end markets such as new broadband solar cells, high-efficiency LEDs, power electronics, new optical devices, and quantum sensors.
Diamond is an excellent insulator due to its ultra-wide band gap of 5.6eV. The simple explanation is that if the electrons in the material want to form an electric current, they need to provide a lot of energy to activate. If the band gap is small, the current is easier to form. The researchers learned that by elastically deforming the diamond nanoneedle, this band gap can be reduced. They achieved this by bending the diamond probe. Experiments have shown that when the amount of strain on the diamond nanoneedle increases, its estimated band gap will shrink, indicating that it has higher conductivity, and this band gap can completely disappear before the needle breaks.