Organic semiconductors have not been realistic candidates for spintronics so far because it was impossible to move spins far enough without losing the original information
Deepak Venkateshvaran
The international team from the UK, Germany and the Czech Republic, have found that these materials could be used for ‘spintronic’ applications, which could make cheap organic semiconductors competitive with silicon for future computing applications. The results are reported in the journal Nature Electronics.
‘Spin’ is the term for the intrinsic angular momentum of electrons, which is referred to as up or down. Using the up/down states of electrons instead of the 0 and 1 in conventional computer logic could transform the way in which computers process information.
Instead of moving packets of charge around, a device built on spintronics would transmit information using the relative spin of a series of electrons, known as a pure spin current. By eliminating the movement of charge, any such device would need less power and be less prone to overheating – removing some of the most significant obstacles to further improving computer efficiency. Spintronics could therefore give us faster, energy-efficient computers, capable of performing more complex operations than at present.
Since organic semiconductors, widely used in applications such as OLEDs, are cheaper and easier to produce than silicon, it had been thought that spintronic devices based on organic semiconductors could power a future computer revolution. But so far, it hasn’t worked out that way.
“To actually transfer information through spin, the electron’s spin needs to travel reasonable distances and live for a long enough time before the information encoded on it is randomised,” said Dr Shu-Jen Wang, a recent PhD graduate of the University of Cambridge’s Cavendish Laboratory, and the paper’s co-first author.
“Organic semiconductors have not been realistic candidates for spintronics so far because it was impossible to move spins around a polymer circuit far enough without losing the original information,” said co-first author Dr Deepak Venkateshvaran, also from the Cavendish Laboratory. “As a result, the field of organic spintronics has been pretty quiet for the past decade.”
Image: Hand sketch of an organic lateral spin pumping device
Credit: Deepak Venkateshvaran and Nanda Venugopal
Reproduced courtesy of the University of Cambridge