nanowires coated with diamond can be up to 100 times better at carrying electric current than bare nanowires at very low temperatures, and two times better at room temperature. This improvement is determined by a property known as electron mobility.
The diamond-coating technique suggested by Balandin and Fonoberov enhances electron mobility in a very different way: “phonon engineering.” Phonons are basic units, or “quanta,” of mechanical vibration; sound waves are examples of acoustic phonons. Phonons play a bothersome role in semiconductor devices by scattering electrons. These problems are compounded when the features of electronic devices are reduced to the nanometer scale.
When a silicon nanowire is surrounded by diamond, the electron-phonon scattering inside the nanowire is suppressed and, as a result, the electron mobility is increased. This is an absolutely new method of mobility enhancement. An added bonus of diamond is that it is an excellent conductor of heat, which could allow it to impart valuable thermal management properties to circuits.