#importing modules
import math
from __future__ import division
#Variable declaration
ni=2.37*10**19; #carrier density(per m**3)
mew_e=0.38; #electron mobility(m**2/Vs)
mew_h=0.18; #hole mobility(m**2/Vs)
e=1.6*10**-19;
#Calculation
sigma_i=ni*e*(mew_e+mew_h);
rho=1/sigma_i; #resistivity(ohm m)
#Result
print "resistivity is",round(rho,3),"ohm m"
#importing modules
import math
from __future__ import division
#Variable declaration
Eg=1.12; #band gap(eV)
T=300; #temperature(K)
m0=1; #assume
me=0.12*m0;
mh=0.28*m0;
k=1.38*10**-23; #boltzmann constant
e=1.6*10**-19;
#Calculation
EF=(Eg/2)+(3*k*T*math.log(mh/me)/(4*e)); #position of fermi level(eV)
#Result
print "position of fermi level is",round(EF,3),"eV"
#importing modules
import math
from __future__ import division
#Variable declaration
T=300; #temperature(K)
k=1.38*10**-23; #boltzmann constant
m=9.109*10**-31; #mass(kg)
h=6.626*10**-34; #plancks constant
Eg=0.7; #energy(eV)
e=1.6*10**-19;
#Calculation
x=(2*math.pi*m*k/h**2)**(3/2);
y=math.exp(-Eg*e/(2*k*T));
ni=2*x*(T**(3/2))*y; #concentration of intrinsic charge carriers(per m**3)
#Result
print "concentration of intrinsic charge carriers is",round(ni/10**18,2),"*10**18 per m**3"
#importing modules
import math
from __future__ import division
#Variable declaration
ni=2.4*10**19; #carrier density(per m**3)
mew_e=0.39; #electron mobility(m**2/Vs)
mew_h=0.19; #hole mobility(m**2/Vs)
e=1.6*10**-19;
#Calculation
sigma_i=ni*e*(mew_e+mew_h);
rhoi=1/sigma_i; #resistivity(ohm m)
#Result
print "resistivity is",round(rhoi,3),"ohm m"
#importing modules
import math
from __future__ import division
#Variable declaration
ni=2.5*10**19; #carrier density(per m**3)
mew_e=0.39; #electron mobility(m**2/Vs)
mew_p=0.19; #hole mobility(m**2/Vs)
e=1.6*10**-19;
l=1*10**-2; #length(m)
A=10**-3*10**-3; #area(m**2)
#Calculation
R=l/(ni*e*A*(mew_p+mew_e)); #resistance(ohm)
#Result
print "resistance is",round(R/10**3,2),"*10**3 ohm"
#importing modules
import math
from __future__ import division
#Variable declaration
T=300; #temperature(K)
k=1.38*10**-23; #boltzmann constant
m=9.109*10**-31; #mass(kg)
h=6.626*10**-34; #plancks constant
Eg=1.1; #energy(eV)
e=1.6*10**-19;
mew_e=0.48; #electron mobility(m**2/Vs)
mew_p=0.013; #hole mobility(m**2/Vs)
#Calculation
C=2*((2*math.pi*m*k/h**2)**(3/2));
y=math.exp(-Eg*e/(2*k*T));
ni=C*(T**(3/2))*y; #concentration of intrinsic charge carriers(per m**3)
sigma_i=ni*e*(mew_e+mew_h); #conductivity(ohm-1 m-1)
#Result
print "conductivity is",round(sigma_i*10**3,3),"*10**-3 ohm-1 m-1"
print "answer given in the book is wrong"
#importing modules
import math
from __future__ import division
#Variable declaration
T=300; #temperature(K)
k=1.38*10**-23; #boltzmann constant
m=9.109*10**-31; #mass(kg)
h=6.626*10**-34; #plancks constant
Eg=0.7; #energy(eV)
e=1.6*10**-19;
mew_e=0.48; #electron mobility(m**2/Vs)
mew_p=0.013; #hole mobility(m**2/Vs)
#Calculation
C=2*((2*math.pi*m*k/h**2)**(3/2));
y=math.exp(-Eg*e/(2*k*T));
ni=C*(T**(3/2))*y; #concentration of intrinsic charge carriers(per m**3)
sigma_i=ni*e*(mew_e+mew_h); #conductivity(ohm-1 m-1)
#Result
print "concentration of intrinsic charge carriers is",round(ni/10**19,2),"*10**19 per m**3"
print "conductivity is",round(sigma_i,3),"ohm-1 m-1"
print "answer in the book varies due to rounding off errors"
#importing modules
import math
from __future__ import division
#Variable declaration
e=1.6*10**-19;
mew_e=0.36; #electron mobility(m**2/Vs)
mew_h=0.17; #hole mobility(m**2/Vs)
rho=2.12; #resistivity(ohm m)
T=300; #temperature(K)
k=1.38*10**-23; #boltzmann constant
m=9.109*10**-31; #mass(kg)
h=6.626*10**-34; #plancks constant
#Calculation
sigma=1/rho;
ni=sigma/(e*(mew_e+mew_h));
C=2*((2*math.pi*m*k/h**2)**(3/2));
y=C*T**(3/2)/ni;
z=math.log(y);
Eg=2*k*T*z/(1.6*10**-19); #forbidden energy gap(eV)
#Result
print "forbidden energy gap is",round(Eg,3),"eV"
print "answer varies due to rounding off errors"
#importing modules
import math
from __future__ import division
#Variable declaration
x=0.6532;
y=0.3010;
T1=273+20; #temperature(K)
T2=273+32; #temperature(K)
k=8.616*10**-5;
#Calculation
dy=x-y;
dx=(1/T1)-(1/T2);
Eg=2*k*dy/dx; #energy band gap(eV)
#Result
print "energy band gap is",round(Eg,3),"eV"
print "answer varies due to rounding off errors"
#importing modules
import math
from __future__ import division
#Variable declaration
k=1.38*10**-23; #boltzmann constant
EF=0.18; #fermi shift(eV)
E=1.2; #energy gap(eV)
e=1.6*10**-19;
r=5;
#Calculation
T=EF*e*4/(3*k*math.log(r)); #temperature(K)
#Result
print "temperature is",round(T),"K"
#importing modules
import math
from __future__ import division
#Variable declaration
Na=5*10**23; #number of atoms(atoms)
Nd=3*10**23; #number of atoms(atoms)
ni=2*10**16; #intrinsic charge carriers(per m**3)
#Calculation
p=2*(Na-Nd)/2; #hole concentration(per m**3)
n=ni**2/p; #electron concentration(per m**3)
#Result
print "electron concentration is",n/10**9,"*10**9 per m**3"
#importing modules
import math
from __future__ import division
#Variable declaration
ni=1.5*10**16; #carrier density(per m**3)
mew_e=0.13; #electron mobility(m**2/Vs)
mew_h=0.05; #hole mobility(m**2/Vs)
e=1.6*10**-19;
d=2.33*10**3; #density(kg/m**3)
n=28.1;
na=6.02*10**26; #number of atoms
#Calculation
sigma=ni*e*(mew_e+mew_h); #conductivity(ohm-1 m-1)
Nd=d*na/(n*10**8);
p=ni**2/Nd;
sigma_ex1=Nd*e*mew_e; #conductivity(ohm-1 m-1)
n=p;
Na=Nd;
sigma_ex2=Na*e*mew_h; #conductivity(ohm-1 m-1)
#Result
print "conductivity is",sigma*10**3,"*10**-3 ohm-1 m-1"
print "conductivity is",round(sigma_ex1,2),"ohm-1 m-1"
print "conductivity is",round(sigma_ex2,2),"ohm-1 m-1"
#importing modules
import math
from __future__ import division
#Variable declaration
ni=1.5*10**16; #carrier density(per m**3)
mew_e=0.135; #electron mobility(m**2/Vs)
mew_h=0.048; #hole mobility(m**2/Vs)
e=1.6*10**-19;
Nd=10**23;
T=300; #temperature(K)
k=1.38*10**-23;
#Calculation
sigma=ni*e*(mew_e+mew_h); #conductivity(ohm-1 m-1)
p=ni**2/Nd; #hole concentration(per m**3)
sigma_ex=Nd*e*mew_e; #conductivity(ohm-1 m-1)
x=3*k*T*math.log(mew_e/mew_h)/4;
#Result
print "conductivity is",sigma*10**3,"*10**-3 ohm-1 m-1"
print "hole concentration is",p,"per m**3"
print "conductivity is",sigma_ex/10**3,"*10**3 ohm-1 m-1"
print "position of fermi level is",round(x/(1.6*10**-19),2),"eV"
#importing modules
import math
from __future__ import division
#Variable declaration
mew_e=0.19; #electron mobility(m**2/Vs)
e=1.6*10**-19;
T=300; #temperature(K)
k=1.38*10**-23;
#Calculation
Dn=mew_e*k*T/e; #diffusion coefficient(m**2 s-1)
#Result
print "diffusion coefficient is",round(Dn*10**4,3),"*10**-4 m**2 s-1"
print "answer varies due to rounding off errors"
#importing modules
import math
from __future__ import division
#Variable declaration
RH=3.66*10**-4; #hall coefficient(m**3/coulomb)
I=10**-2; #current(amp)
B=0.5; #magnetic field(wb/m**2)
t=1*10**-3; #thickness(m)
#Calculation
VH=RH*I*B*10**3/t; #hall voltage(mV)
#Result
print "hall voltage is",VH,"mV"
#importing modules
import math
from __future__ import division
#Variable declaration
Vy=37*10**-6; #voltage(V)
t=10**-3; #thickness(m)
Bz=0.5; #magnetic field(wb/m**2)
Ix=20*10**-3; #current(A)
#Calculation
RH=Vy*t/(Ix*Bz); #hall coefficient(m**3/coulomb)
#Result
print "hall coefficient is",RH,"C-1 m**3"
#importing modules
import math
from __future__ import division
#Variable declaration
RH=6.85*10**-5; #hall coefficient(m**3/coulomb)
e=1.6*10**-19;
sigma=250; #conductivity(m-1 ohm-1)
#Calculation
n=1/(RH*e); #density of charge carriers(m**3)
mew=sigma/(n*e); #mobility of charge carriers(m**2/Vs)
#Result
print "density of charge carriers is",round(n/10**22,3),"*10**22 m**3"
print "mobility of charge carriers is",mew*10**3,"*10**-3 m**2 V-1 s-1"
#importing modules
import math
from __future__ import division
#Variable declaration
I=30; #current(A)
B=1.75; #magnetic field(T)
n=6.55*10**28; #electron concentration(/m**3)
t=0.35*10**-2; #thickness(m)
e=1.6*10**-19;
#Calculation
VH=I*B*10**6/(n*e*t); #hall voltage(micro V)
#Result
print "hall voltage is",round(VH,3),"micro V"
#importing modules
import math
from __future__ import division
#Variable declaration
RH=3.66*10**-4; #hall coefficient(m**3/coulomb)
e=1.6*10**-19;
Pn=8.93*10**-3; #resistivity(ohm m)
#Calculation
n=1/(RH*e); #density of charge carriers(per m**3)
mew_e=RH/Pn; #mobility of charge carriers(m**2/Vs)
#Result
print "density of charge carriers is",round(n/10**22,3),"*10**22 per m**3"
print "mobility of charge carriers is",round(mew_e,3),"m**2 V-1 s-1"