Sandwiches set to take diodes beyond silicon

Their approach is based on the assumption that electrons move too slowly through silicon and that MIM diodes will enable applications that would not be possible with silicon based materials. The diodes consist of a 'sandwich' of inexpensive and environmentally benign materials. Two metals, with two insulators in between, form MIIM devices. This structure allows electrons to tunnel through insulators and appear almost instantaneously on the other side. According to the team, it's a fundamentally different approach to electronics. The work is said to show that the addition of a second insulator can enable 'step tunnelling', where an electron may tunnel through only one of the insulators instead of both. This allows precise control of diode asymmetry, non-linearity and rectification at lower voltages. "This approach enables us to enhance device operation by creating an additional asymmetry in the tunnel barrier," said Professor John Conley, from OSU's School of Electrical Engineering and Computer Science. "It gives us another way to engineer quantum mechanical tunnelling and moves us closer to the real applications that should be possible with this technology." The team believes MIIM diodes will enable more sophisticated products, including improved liquid crystal displays, mobile phones and tvs.