What is Gunn Diode?: Working, Characteristics & Applications
A Gunn diode is a semiconductor device. This device is also called as a transferred electron device — TED. Gunn diode is two terminal semiconductor components with negative resistance. It is based on “Gunn effect” and invented by physicist scientist J. B. Gunn in 1962. It is masterly use in electronics oscillator to generate microwave frequency, in applications such as radar speed guns, microwave relay data link transmitters and automatic door openers. In this article we are going to discuss an overview Gunn diode and how it work with applications.
WHAT IS A GUNN DIODE?
Gunn diode is two terminals semiconductor diode, which compose of only an n-doped semiconductor material, unlike other diodes which consist of a p-n junction. A Gunn diode is works on Gunn Effect. It can be made of like Gallium Arsenide (GaAs), Zinc Selenide (ZnSe), Gallium Nitride (GaN), Cadmium Sulfide (CdS), Cadmium Telluride (CdTe), Indium Antimonide (InSb), Indium Arsenide (InAs) and Indium Phosphide (InP), which consist of multiple, initially-empty, closely-spaced energy valleys in their conduction band.
GUNN DIODE CONSTRUCTION
The construction of Gunn diode is done with N type of semiconductor. The frequently use of material are gallium Arsenide (GaAs) & Indium Phosphide (InP) and other materials.
It uses N type material because the effect of transferred electron is simply appropriate to electrons and not holes found in a p-type material. This component has three regions which are top middle and bottom.
The construction of Gunn diode procedure is from an epitaxial layer of on a degenerate n+ substrate to form three n-type semiconductor layers, n+ layer are extremely doped as compare to middle n layer. The dimension of active layer is few microns to 100 microns and the doppped layer is from1014cm-3 to 1016cm-3. The dimension of layer can be changes according to the required frequency. Further it is connected width metal contact at either end of Gunn diode to facilitate biasing.
GUNN DIODE SYMBOL
The symbol of Gunn diode is seen like a two triangle with point contact of one vertex. The symbol of Gunn diode is shown in below.
