Explain einstein relation, Electrical Engineering

Assignment Help:

Explain Einstein relation.

Einstein relation:

There exists a significant relation between the diffusion constant and the mobility. It is termed as the Einstein relation and may be deduced as given below:

Consider a semiconductor wherein there exists an electric field Ex and a concentration gradient as the current is zero. In these conditions the system is in the Boltzmann statistics and thermal equilibrium applies. Consider a potential V(x) producing at x an electric field E(x)= -dV/dx.

For the density of holes the Boltzmann expression as a function of x in thermal equilibrium is as

p(x) = Ce-eV/KT

Here C is a constant.

Therefore the gradient of the hole density is given by

dp/dx = (-e/KT)p.(dv/dx)

= (e/KT)p.E

The hole current vanishes in thermal equilibrium. Therefore,

O=peup Ex-eDp  dp/dx

=peup Ex-(e2 /KT)Dp . Ex

Dp = (KT/e) Up (i.e. the Einstein relation).


Related Discussions:- Explain einstein relation

Define voltage source multiplying dac, Define Voltage Source Multiplying DA...

Define Voltage Source Multiplying DAC? Voltage source multiplying DACs use a reference voltage which is switched in or out by the digital data.  The converter is so-named becau

Example of high resistivity material, Example of high resistivity material ...

Example of high resistivity material is (A) Nichrome              (B) Silver (C) Gold                      (D) Copper Ans: Nichrome is example of high resistivity

Functions of the physical layer in the internet model, (a) Describe the f...

(a) Describe the four functions of the physical layer in the Internet Model. (b) (i) With the help of a diagram describe the main stages involved in the digitization of a

Critical rate of rise of current - thyristor , Critical Rate of  Rise of ...

Critical Rate of  Rise of Current The maximum  rate of  increase of current  during  on state  which  the SCR  can tolerate is called  the critical rate of rise  of current  f

Explain kirchhoff current law, Q. Explain Kirchhoff current law? The ba...

Q. Explain Kirchhoff current law? The basic laws that must be satisfied among circuit currents and circuit voltages are known as Kirchhoff 's current law (KCL) and Kirchhoff 's

Relative permeability, The force between two wires 1 metre apart and each c...

The force between two wires 1 metre apart and each carrying 1 amp is 2 x 10 -7 Newtons when in a vacuum (or in practice, air).However, it is found experimentally that the force is

Calculate the instantaneous and rms values, Q. The flux-density distributio...

Q. The flux-density distribution in the air gap of a 60-Hz, two-pole, salient-pole machine is sinusoidal, having an amplitude of 0.6 T. Calculate the instantaneous and rms value

Determine the type of the semiconductor, Determine the Type of the Semicond...

Determine the Type of the Semiconductor An unknown semiconductor has E g =1.1 eV and N t =N v . lt is doped with 10 16 /cm 3 donor atoms. - (a) Determine the type of the s

DC generator, define all the symbols with their units of DC generater

define all the symbols with their units of DC generater

Plc and control system analysis, The assignment is to plan, design and writ...

The assignment is to plan, design and write a PLC program on the FX Training Software using a PART SUPPLY CONTROL SYSTEM based on the requirement specification outlined be

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