Schottky barrier diodes, Physics

Assignment Help:

 

The Schottky diodes are a semiconductor diode with a low forward voltage drop and a very fast switching action. The voltage drop at forward biases of around 1ma is in the range 0.15v to 0.45v, which makes them useful in voltage clamping application and prevention of transistor saturation. This is because of high current density. Its areas of applications were first limited to the very frequency range due to its quick response time (especially important in frequency applications). In recent years, however it is appearing more and more in low voltage/high current power supplies and AC to DC converts. Other areas of applications of the device including radar systems, Schottky TTL logic for compounds, mixers and detectors in communication equipment, instrumentations, and analogue to digital converters. A Schottky diode uses a metal semiconductor junction as a Schottky barrier (instead of a semiconductor junction as in conventional diodes). Its construction is pretty dissimilar from the conventional P-N junction. The semiconductor is normally n-type silicon (although p-type silicon is sometimes used), while a host of different metals such as molybolenum, platinum, chrome or tungsten are used. In general, however, Schottky diode construction results in a more uniform junction and of ruggedness. In both materials the electrons is the majority carriers. When the materials are joined, the electron in the N-type silicon semiconductor material immediately flows into the adjoining material, establishing a heavy flow of majority carriers. As the injected carriers have a very elevated kinetic energy level as compare to the electrons of the metal, they are usually called “ hot carriers”, the heavy flow of electrons into the metal generates a region close to the junction surface depleted of carriers in the silicon material much like the depletion region in the P-N junction diode. The additional carriers in the metal set up a “negative wall” in the metal at the margin between the two materials. The net consequence is a surface barrier between the two materials preventing any additional current. That is any electrons in the silicon material face a carrier free region and a “negative wall” at the surface on the metal. The application of forward bias will reduce the strength of the negative barrier through the attraction of the applied positive voltage for electrons from this region. The result is a result to the heavy flow electrons across the boundary, the magnitude of which is controlled by the level of the applied bias potential.


Related Discussions:- Schottky barrier diodes

Calculate the overall heat loss coefficient, Calculate the overall heat-los...

Calculate the overall heat-loss coefficient for a solar collector with a single glass cover having the following specifications (neglect edge effects): Spacing between the plate

Third harmonic- standing waves on a string, Third Harmonic- Standing Waves ...

Third Harmonic- Standing Waves on a String There are a variety of patterns that could be generates through vibrations inside slinky, a string, or rope. Each pattern corresponds

Physics, Current time base generator

Current time base generator

Define the ray diagrams for lenses, Define the Ray Diagrams for Lenses Wh...

Define the Ray Diagrams for Lenses When drawing ray diagrams for thin lenses, we can assume that the lens is infinitely thin. Instead of considering refractions at each surface o

Derive an expression for the torque acting on a loop, Derive an expression ...

Derive an expression for the torque acting on a loop of N turns, area A, carrying current i, when held in a uniform magnetic field. With the help of ciruit, show how a moving coil

Heavy water is often used as a moderator in thermal nuclear, 'Heavy water i...

'Heavy water is often used as a moderator in thermal nuclear reactors.' Give reason.

Cosmic censorship conjecture, Cosmic censorship conjecture (R. Penrose, 197...

Cosmic censorship conjecture (R. Penrose, 1979) The conjecture, so far completely undemonstrated in the context of general relativity, that all singularities (along the possib

Xrd, Suppose that a nickel filter is required to produce an intensity ratio...

Suppose that a nickel filter is required to produce an intensity ratio of Cu K a to Cu K ß of 100/1 in the filtered beam. Calculate the thickness of the filter and the transmission

Find the electric flux density, Two parallel plates having a p.d. of 250V b...

Two parallel plates having a p.d. of 250V between them are spaced 1mm apart. Determine the electric field strength. Find also the electric flux density when the dielectric a

Calculate uniform magnetic field, The greatest induced EMF will happen in a...

The greatest induced EMF will happen in a straight wire moving at constant speed by a uniform magnetic field. when the angle among the direction of the wire's motion and the di

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd