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

Microprocessors, Memory location 2000H has the word 5000H stored in it. Wha...

Memory location 2000H has the word 5000H stored in it. What does each location contain after DEC WORD PTR [2000H].

Explain the meaning of synchronous counters, Explain the meaning of Synchro...

Explain the meaning of Synchronous Counters? In the synchronous counters the clock inputs of all the flip-flops are connected together and are triggered by the input pulses, the

Microcontroller interfacing, The winch uses a 415 Volt 50 Hz AC motor, so b...

The winch uses a 415 Volt 50 Hz AC motor, so both the up/down and run/stop controls actually operate +24V relays, whose contacts switch the 415Vac to the winch. The relays also pro

Three phase ac circuit, Three Phase AC Circuit: Alternating circuits t...

Three Phase AC Circuit: Alternating circuits thus far discussed have single phase supply system and it's satisfactory for domestic application as light, fan and heating, etc.

Binary number system - number systems , Binary  Number Systems As men...

Binary  Number Systems As mentioned  earlier this  number is used by  digital  systems like  microprocessor  and other  digital  circuits. This  number  systems  use only two

Instrumentation, explain measurement of frqueny and phase using cro

explain measurement of frqueny and phase using cro

Transparent latch d flip flop, Transparent latch D flip  Flop A typica...

Transparent latch D flip  Flop A typical  example  of this  type of D flop  is 7475 shown  in figure when CLK  connected is enable signal is high and the flip  flop  is enabled

The filter capacitor , It is needed to use a half-wave rectifier for a dc p...

It is needed to use a half-wave rectifier for a dc power supply that gives an average dc output voltage of 15 V and a maximum ±1V ripple is permitted. The rectifier feeds a load of

Draw a one-line diagram of three-phase distribution system, Q. A three-phas...

Q. A three-phase transformer bank consisting of three 10-kVA, 2300:230-V, 60-Hz, single-phase transformers connected in Y- is used to step down the voltage. The loads are connecte

Forward voltage triggering , Forward Voltage  Triggering If V a is i...

Forward Voltage  Triggering If V a is increased the collector to emitter voltages of both  transistor are  also increased. Hence  the leakage current at J 2 increase. This

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