Semiconductor in equilibrium, Electrical Engineering

Assignment Help:

Semiconductor in Equilibrium

Equilibrium in semiconductors implies the following:

(i) Steady state: ∂Z / ∂t = 0

In which Z is any physical quantity like charge, voltage electric field etc.

(ii) No net thermal Currents and electrical current:

Because current can be carried via both electrons and holes, equilibrium involves zero values for both of the net electron current and net hole current. The drift and diffusion components of electron and hole currents require not be zero.

(iii) Constant Fermi energy:  dEF / dX = 0

The only one equations that are relevant (another being zero!) for analysis in equilibrium are:

Poisson Equation:

2Ψ0 / ∂x2 = - q/ε (p0 - n0 + ND+ - NA-)

n0 = ni exp (EF - Ei / KT)

P0 = ni exp (Ei - EF / KT)

n0 p0 = n2i                

In equilibrium, there is only single independent variable out of the three variables:  

n0, p0, Ψ0

If one of them is well known, all the rest can be measured from the equations listed above. We shall consider this independent variable to be potential. The analysis trouble in equilibrium is hence determination of potential or equivalently, energy band diagram of the semiconductor device. This is the cause why we begin discussions of all semiconductor devices with a sketch of the energy band diagram of it in equilibrium.


Related Discussions:- Semiconductor in equilibrium

Evaluate a single-stage transistor amplifier, Design and using Pspice, eval...

Design and using Pspice, evaluate a single-stage transistor amplifier amplifier to meet the following specifications: * Power supply - 12V dc. · *Voltage gain - 120 when Vin

Name all the switching schemes used in a digital exchange, Q. Name all the ...

Q. Name all the switching schemes used in a digital exchange. How call processing occur? Ans: The basic types of switching systems used are: 1.  Stronger Switching System

What is a bode plot and what are i''s uses, Q. (i) What are the different t...

Q. (i) What are the different types of plots for frequency response in an RC coupled amplifier?     (ii) What is a Bode Plot? What are it's uses? The different types of

Explain acceptance cone, Explain Acceptance cone? The fibre air - core ...

Explain Acceptance cone? The fibre air - core interface is display below: In this figure Omax is the maximum angle, inside that the rays undergo total internal reflecti

How you can convert a galvanometer to a voltmeter, To convert a galvanomete...

To convert a galvanometer to a voltmeter, you should add a: a) High resistance in series b) High resistance in parallel c) Low resistance in series d) Low resis

Transformer, A6KVA,100V/500V single-phase transformer has a secondary termi...

A6KVA,100V/500V single-phase transformer has a secondary terminal voltage of 487.5 volts when loaded. determine the regulation of the transformer

Bathub curve, what is an useful life time in bathtub curve?

what is an useful life time in bathtub curve?

Magnetism, What is mgnomotive force

What is mgnomotive force

Steps to develop microprocessor based computer system, Explain in brief ste...

Explain in brief steps to develop a Microprocessor based computer system. The design of a microcomputer system should begin with the CPU module. It modules establishes the fund

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