Organic Molecules Replace Silicon-based Transistors

Silicon is the edifice of electronics revolution. With the help of silicon, microchips are made and they are used as integrated circuit (I.C.) in a variety of electronic appliances like TV, computer, etc. Transistors made of silicon switch electric current on and off. In a single silicon chip there are hundreds of thousands of tiny transistors. As a result, the size of a computer in the early stage was as large as a room, which later shrank to pocket-sized PC.

In the University of Arizona, the scientists made a breakthrough. In this team, there is an NRI (nonresident Indian) named Sumit Mazumdar. They showed that single organic molecules can replace silicon based transistors. Their work has been published in Nano letters journal of November 2006 issue. Professor Charles Stafford and a post doctoral fellow Cardamone explored this possibility which remained a theoretical possibility.

The technique is different and fascinating. In 2005, the team showed for the first time that a single charged atom on a silicon surface can regulate the conductivity of a nearby molecule, thereby allowing current to pass through. The scientists named their device as QuIET i.e. Quantum Inference Effect Transistor.

The simplest molecule proposed for transistor is benzene. They propose attaching two electrical leads to the ring to create two alternate paths through which current can flow.

Advantage of QuIET:

Since current is regulated by quantum interference, instead of raising or lowering barrier, QuIET could be operated at a much lower power level.
The interference effect upon which QuIET is based is insensitive to other electrostatic changes that occur in molecules.