Ch-5 : Special Diodes

Page No. 132 Exmaple 5.1.

from math import log
thetaM=4.26 #work function
chi=4.01 #electron affinity
thetaBN=thetaM-chi
print "The barrier height for N-type material is,"
print "    Theta_BN = Theta_M - Chi = %0.2f V"%thetaBN
thetaIN=thetaBN-((((1.38*10**-23)*300)/(1.6*10**-19)))*log((2.8*10**25)/(4*10**17))
print "The built-in potential is given by,"
print "    Theta_IN = Theta_BN - (kT/q)*ln(NC/ND) =%0.2f V"%thetaIN 
# answer in the textbook is wrong, even if we take log10 we get a answer 0.047.

The barrier height for N-type material is,
    Theta_BN = Theta_M - Chi = 0.25 V
The built-in potential is given by,
    Theta_IN = Theta_BN - (kT/q)*ln(NC/ND) =-0.22 V