Single Electron Transistors

Nanotechnology is ushering in the era of self-replicating machinery and self-assembling consumer goods made from raw atoms. Utilizing the well understood properties of atoms & molecules, nanotechnology proposes the construction of novel molecular devices possessing extraordinary properties. The single electron transistor or SET is a new type of switching device that uses controlled electron tunnelling to amplify current. It is a key element of current research area of nanotechnology which can offer low power consumption and high operating speed. Single electron transistor [SET] is a new nanoscaled switching device because single-electron transistor retains its scalability even on an atomic scale and besides this; it can control the motion of a single electron. Here, scalability means that the performance of electronic devices increases with a decrease of the device dimensions. By using the “Electron beam lithography” and “Electromigration”, the research leads to the designing of a single atom transistor with the help of the meticulously synthesized semiconductor crystals called “quantum dots”, which embodies the electrons confined in a channel and resembles same in its properties as a real atom. Whereas we can understand conventional transistors using classical concepts, the SET is quantum mechanical in an essential way. In fact, there is a close analogy between the confined electrons inside an SET and an atom. In this paper, the physics underlying the operation of SETs is explained, a brief history of its invention is presented, and issues of current interest are discussed.