Chapter 19 : Semiconductor-Device Physics

Example 19.1, Page No 808

import math
#initialisation of variables
sg=0.971*10**3     #g/cm^3 specific gravity
w=22.99*1.66*10**-27   # Weight of a sodium atom

#Calculations
n=sg/w
Ef=3.64*10**-19*(n**(2.0/3))

#Results
print("The value of n is %.2f  /m^3 x 10^28 " %(n/10**28))
print("The value of Ef is %.2f  eV" %(Ef))

The value of n is 2.54  /m^3 x 10^28 
The value of Ef is 3.15  eV

Example 19.2, Page No 810

import math
#initialisation of variables
E=0.05     #eV

#Calculations
NE=6.82*10**27*(E**(1.0/2))

#Results
print("The value of NE is %.2f  X 10^27 /m^3 " %(NE/10**27))

The value of NE is 1.52  X 10^27 /m^3 

Example 19.3, Page No 812

import math
#initialisation of variables
KE=0.26*1.6*10**-19    #j kinetic energy
m=9.18*10**-31

#Calculations
Vav=math.sqrt((2.0*KE)/m)

#Results
print("The value of Vav is %.2f  x 10^5" %(Vav/10**5))

The value of Vav is 3.01  x 10^5

Example 19.4, Page No 815

import math
#initialisation of variables
ni1=1.5*10**10   #cm^3
T2=873.0     #k
T1=300.0     #k
Eg0=1.0



#Calculations
ni2=math.sqrt((ni1**2)*(T2/T1)*math.exp((1.21/8.625*10**-5)*(-(1/T2)+(1/T1))))

#Results
print("The value of ni2 is %.2f x 10^17 cm^3" %(ni2/10**10))

The value of ni2 is 2.56 x 10^17 cm^3

Example 19.5, Page No 817

import math
#initialisation of variables
kT=0.026
Nc=2.89*10**19
Nd=10**16

#Calculations
Ef=kT*(math.log((Nc/Nd),2))

#Results
print("The value of Ef is %.2f eV" %(Ef))

The value of Ef is 0.30 eV

Example 19.6, Page No 830

import math

#initialisation of variables
I1=1.0    #mA
Vt=26.0     #mV
tP=10**-6

#Calculations
g=(I1/Vt)
Cd=(g*tP)/2

#Results

print("The value of Cd is %.2f nF" %(Cd*10**9))

The value of Cd is 19.23 nF