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

Illustrate procedure of hex to binary conversion, Q. Illustrate procedure o...

Q. Illustrate procedure of Hex to Binary Conversion? It is also simple to convert from an integer hex number to binary. This is achieved by: Convert the Hex number t

Function of circuit - breaker, Q. Function of circuit - breaker, difference...

Q. Function of circuit - breaker, difference between circuit breaker and 'isolator'? Ans: The function of circuit breaker is to break the electrical continuity in the event o

Loops and subroutines, 1.....If viewing this through the Assignment tool, c...

1.....If viewing this through the Assignment tool, click the title above to go to the Submissions area. Introduction The purpose of this experiment is to examine the opera

Application of microprocessors , Application of Microprocessors Microp...

Application of Microprocessors Microprocessor microcontroller based systems  may be used  in almost  every filed of life  and  their  applications  are increasing day by day

Find the small-signal equivalent circuit parameters, Given that a BJT has β...

Given that a BJT has β = 60, an operating point defined by I CQ = 2.5 mA, and an Early voltage V A = 50 V. Find the small-signal equivalent circuit parameters g m , r o , and rπ.

Three byte instruction , Three byte instruction The  instruction which...

Three byte instruction The  instruction which  have 16  bit data address  as its  operand  are three byte  instruction. They  need three  memory  locations to store  them in m

Threshold switching voltage, Analogue Threshold switching a) Include a...

Analogue Threshold switching a) Include a variable potential divider to the schematic diagram to control the transistor base voltage b) Include the potential divider compon

Compare mosfet with jfet, Q. Compare MOSFET with  JFET? a. In enhanceme...

Q. Compare MOSFET with  JFET? a. In enhancement and depletion types of MOSFET,the transverse electric field induced across an insulating layer deposited on the semiconductor ma

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