initial commit / add all books

13 files changed, 272 insertions, 0 deletions

diff --git a/2792/CH2/EX2.1/Ex2_1.sce b/2792/CH2/EX2.1/Ex2_1.sce
new file mode 100755
index 000000000..d1b13db45
--- /dev/null
+++ b/2792/CH2/EX2.1/Ex2_1.sce
@@ -0,0 +1,14 @@
+clc

+h=1.05*10^-34

+disp("h = "+string(h)+"Js") //initializing value of reduced plancks constant or dirac constant or h-bar

+mo = 9.1*10^-31

+disp("mo = "+string(mo)+"kg") //initializing value of mass of electron

+E = 0.1*1.6*10^(-19)

+disp("E= "+string(E)+"J")//initializing value of Energy of electron in conduction band

+m=0.067*mo

+disp("m = "+string(m)+"kg") //initializing value of appropriate mass in the conduction band for GaAs

+k = sqrt(2*m*E)/h

+disp("The k-value for an electron in the conduction band of GaAs is ,(k = sqrt(2*m*E)/h)= "+string(k)+"m^-1")//calculation

+ko = 1.625*10^9

+disp("The k-value for an electron in the free space is ,ko = "+string(ko)+"m^-1")// initializing k value of electron in the free space

+disp("the two value are quite difference since the k value represent effective momentum")

diff --git a/2792/CH2/EX2.10/Ex2_10.sce b/2792/CH2/EX2.10/Ex2_10.sce
new file mode 100755
index 000000000..17b31fd63
--- /dev/null
+++ b/2792/CH2/EX2.10/Ex2_10.sce
@@ -0,0 +1,22 @@
+clc

+mo = 9.1*10^-31

+disp("mo = "+string(mo)+"kg") //initializing value of mass of electron

+me = 0.067*mo

+disp("me* = "+string(me)+"kg") //initializing value of effective mass of GaAs

+kbT = 0.026

+disp("kbT = "+string(kbT)+"eV/K") //initializing value of kbT at 300K

+ml = 0.98*mo

+disp("ml* = "+string(ml)+"kg") //initializing value of longitudinal mass

+mt = 0.19*mo

+disp("mt*= "+string(mt)+"kg")//initializing value of transverse mass

+mh = 0.55*mo

+disp("mh*= "+string(mh)+"kg")//initializing value of density of state mass for the valence band 

+//let

+Eg = 0.0

+disp("Eg = "+string(Eg)+"J") //initializing value of valence bandedge energy

+mdos = (((6)^(2/3))*((ml)*((mt)^2))^(1/3))

+disp("The desity of states of effective mass of the combined six valleys of silicon is (mdos* = (((6)^(2/3))*((ml*)*((mt*)^2))^(1/3)))= "+string(mdos)+"kg")//calculation

+Efi = (Eg/2)+((3/4)*kbT*log(mh/mdos))

+disp("The intrinsic fermi level is given by Efi = (Eg/2)+((3/4)*kbT*log(mh/me))= "+string(Efi)+"eV")//calculation

+// -ve sign show that fermi level is below the centre of mid-bandgap

+// In this question the answer is provided in the book is in terms of Eg and i have assumed value of Eg = 0 V 

diff --git a/2792/CH2/EX2.11/Ex2_11.sce b/2792/CH2/EX2.11/Ex2_11.sce
new file mode 100755
index 000000000..71ef4cc01
--- /dev/null
+++ b/2792/CH2/EX2.11/Ex2_11.sce
@@ -0,0 +1,20 @@
+clc

+mo = 9.1*10^-31

+disp("mo = "+string(mo)+"kg") //initializing value of mass of electron

+me = 0.027*mo

+disp("me* = "+string(me)+"kg") //initializing value of effective mass of GaAs

+kbT = 0.026

+disp("kbT = "+string(kbT)+"eV") //initializing value of kbT at 300K

+mh = 0.4*mo

+disp("ml* = "+string(mh)+"kg") //initializing value of longitudinal mass

+h=1.05*10^-34

+disp("h= "+string(h))//initializing value of plank constant.

+Eg = 0.35

+disp("Eg = "+string(Eg)+"J") //initializing value of valence bandedge energy

+ni =2*(((kbT*1.6*10^-19)/(2*(%pi)*h^2))^(3/2))*((me*mh)^(3/4))*(exp(-Eg/(2*kbT)))

+disp("ni =2*(kbT/(2*(%pi)*h^2))^(3/2)*((me*mh)^(3/4))*(exp(-Eg/(2*kbT)))= "+string(ni)+"m^-3")//calculation

+kbT = 0.05175

+disp("kbT = "+string(kbT)+"eV") //initializing value of kbT at 600K

+ni =2*(((kbT*1.6*10^-19)/(2*(%pi)*h^2))^(3/2))*((me*mh)^(3/4))*(exp(-Eg/(2*kbT)))

+disp("ni =2*(kbT/(2*(%pi)*h^2))^(3/2)*((me*mh)^(3/4))*(exp(-Eg/(2*kbT)))= "+string(ni)+"m^-3")//calculation

+//Note: In the textbook wrong answer is given for intrinsic carrier concentration at 600K

diff --git a/2792/CH2/EX2.12/Ex2_12.sce b/2792/CH2/EX2.12/Ex2_12.sce
new file mode 100755
index 000000000..2afe905f3
--- /dev/null
+++ b/2792/CH2/EX2.12/Ex2_12.sce
@@ -0,0 +1,32 @@
+clc

+mo = 9.1*10^-31

+disp("mo = "+string(mo)+"kg") //initializing value of mass of electron

+m_star=0.067*mo

+disp("m_star=0.067*mo = "+string(m_star)+"kg") //initializing value of appropriate mass in the conduction band for GaAs

+apsilen = 13.2*8.85*10^-14

+disp("apsilen = "+string(apsilen)+"F/cm") //initializing value of relative permitivity for GaAs

+apsilen_not = 8.85*10^-14

+disp("apsilen_not = "+string(apsilen_not)+"F/cm") //initializing value of permitivity

+ml = 0.98*mo

+disp("ml* = "+string(ml)+"kg") //initializing value of longitudinal mass

+mt = 0.2*mo

+disp("mt*= "+string(mt)+"kg")//initializing value of transverse mass

+m_sigma_star = (3)/((1/ml)+(2/mt))

+disp("The conductivity mass for silicon is ,m_sigma_star = (3*mo)/((1/ml)+(2/mt))= "+string(m_sigma_star)+"Kg")//calculation

+disp("The shallow level energies are given by,Ed = Ec-(13.6(eV)*((m_star/mo)/(apsilen/apsilen_not)^2))")

+//Let Ec = 0 V and taking positive answer, 

+Ed_GaAs = (13.6*((m_star/mo)/(apsilen/apsilen_not)^2))

+disp("The donor level energy in GaAs is ,Ed_GaAs = Ed = (13.6*((m_star/mo)/(apsilen/apsilen_not)^2))= "+string(Ed_GaAs)+"eV")//calculation

+m_dot_GaAs=0.45*mo

+disp("m_dot_GaAs=0.45*mo = "+string(m_dot_GaAs)+"kg") //initializing value of heavy hole mass for GaAs

+Ea_GaAs = (13.6*((m_dot_GaAs/mo)/(apsilen/apsilen_not)^2))

+disp("The acceptor level energy in GaAs is ,Ea_GaAs = (13.6*((m_dot_GaAs/mo)/(apsilen/apsilen_not)^2))= "+string(Ea_GaAs)+"eV")//calculation

+apsilen = 11.9*8.85*10^-14

+disp("apsilen = "+string(apsilen)+"F/cm") //initializing value of relative permitivity for GaAs

+m_dot_Si=0.5*mo

+disp("m_dot_Si=0.45*mo = "+string(m_dot_Si)+"kg") //initializing value of heavy hole mass for GaAs

+Ea_Si = (13.6*((m_dot_Si/mo)/(apsilen/apsilen_not)^2))

+disp("The acceptor level energy in Si is ,Ea_Si = (13.6*((m_dot_Si/mo)/(apsilen/apsilen_not)^2))= "+string(Ea_Si)+"eV")//calculation

+Ed_Si = (13.6*((m_sigma_star/mo)/(apsilen/apsilen_not)^2))

+disp("The donor level energy in Si is ,Ed_Si = (13.6*((m_sigma_star/mo)/(apsilen/apsilen_not)^2))= "+string(Ed_Si)+"eV")//calculation

+// Note : due to different precisions taken by me and the author ... my answer differ 

diff --git a/2792/CH2/EX2.13/Ex2_13.sce b/2792/CH2/EX2.13/Ex2_13.sce
new file mode 100755
index 000000000..db71db98b
--- /dev/null
+++ b/2792/CH2/EX2.13/Ex2_13.sce
@@ -0,0 +1,16 @@
+clc

+n = 10^17

+disp("n = "+string(n)+"cm^-3") //initializing value of free density of electron of GaAs

+kBT=0.026

+disp("kBT = "+string(kBT)+"eV") //initializing value of multiplication of boltzmann constant and temperature 

+Nc = 4.45*10^17

+disp("Nc = "+string(Nc)+"cm^-3") //initializing value of effective density of electron

+//(we have assumed the valence band energy Ev=0eV as it is not provided in the book)

+E1= kBT*((log(n/Nc)))

+disp("Ef(B)= kBT*((log(n/Nc)))= "+string(E1)+"eV")//calculation

+E2= kBT*((log(n/Nc))+(1/sqrt(8))*(n/Nc))

+disp("E(J)= kBT*((log(n/Nc))+(1/sqrt(8))*(n/Nc))= "+string(E2)+"eV")//calculation

+//for Boltzmann approximation the carrier concentration and fermi level are related as : Ef = Ec+E1

+//for joyce dixon approximation the carrier concentration and fermi level are related as : Ef = Ec+E2

+e=E1-E2

+disp("The error produced by using boltzmann approx. is  e=E1-E2= "+string(e)+"eV")//calculation

diff --git a/2792/CH2/EX2.14/Ex2_14.sce b/2792/CH2/EX2.14/Ex2_14.sce
new file mode 100755
index 000000000..a8b9ace97
--- /dev/null
+++ b/2792/CH2/EX2.14/Ex2_14.sce
@@ -0,0 +1,12 @@
+

+clc

+disp("In the Boltzmann approximation, the carrier density is simply")

+disp("n = Nc = 2.78*10^19 cm^-3")

+N=2.78*10^19

+disp("N = "+string(N)+"cm^-3") //initializing value of carrier density

+//In joyce dixon approximation the carrier density is obtained from the solution of the equation

+disp("Ef = 0 = kBT *(log(n/Nc)+(n/(sqrt8*Nc)))")

+//solving by trial and error , we get

+//n/Nc= 0.76

+n=0.76*N

+disp("electron carrier concentration is n=0.76*Nc= "+string(n)+" cm^-3")//calculation

diff --git a/2792/CH2/EX2.16/Ex2_16.sce b/2792/CH2/EX2.16/Ex2_16.sce
new file mode 100755
index 000000000..80c1e26ea
--- /dev/null
+++ b/2792/CH2/EX2.16/Ex2_16.sce
@@ -0,0 +1,20 @@
+clc

+Nc = 2.8*10^19

+disp("Nc = "+string(Nc)+"cm^-3") //initializing value of effective density of electron

+Nd = 10^16

+disp("Nd = "+string(Nd)+"cm^-3") //initializing value of donor atom

+Ec_minus_Ed = 45*10^-3

+disp("Ec_minus_Ed = "+string(Ec_minus_Ed)+"eV") //initializing value of donor binding energy

+kBT=0.026

+disp("kBT = "+string(kBT)+"eV") //initializing value of multiplication of boltzmann constant and temperature 

+//let fraction of ionised donor are represented as Fd = (nd/(n+nd))

+Fd= (1/(((Nc/(2*Nd))*exp(-(Ec_minus_Ed/kBT)))+1))*100

+disp("fraction of ionised donor is Fd= 1/(((Nc/(2*Nd))*exp(-(Ec_minus_Ed/kBT)))+1)= "+string(Fd)+"%")//calculation

+Nd = 10^18

+disp("Nd = "+string(Nd)+"cm^-3") //initializing value of donor atom

+Fd= (1/(((Nc/(2*Nd))*exp(-(Ec_minus_Ed/kBT)))+1))*100

+disp("fraction of ionised donor is Fd= 1/(((Nc/(2*Nd))*exp(-(Ec_minus_Ed/kBT)))+1)= "+string(Fd)+"%")//calculation

+// Note : due to different precisions taken by me and the author ... my answer differ 

+

+

+

diff --git a/2792/CH2/EX2.17/Ex2_17.sce b/2792/CH2/EX2.17/Ex2_17.sce
new file mode 100755
index 000000000..86b1b2e89
--- /dev/null
+++ b/2792/CH2/EX2.17/Ex2_17.sce
@@ -0,0 +1,13 @@
+clc

+Nc_Si = 2.78*10^19

+disp("Nc_Si = "+string(Nc_Si)+"cm^-3") //initializing value of effective density of electron for silicon

+Nc_GaAs = 4.45*10^17

+disp("Nc_GaAs = "+string(Nc_GaAs)+"cm^-3") //initializing value of effective density of electron for GaAs

+disp("for joyce dixon approximation the carrier concentration and fermi level are related as : Ef -Ec = kBT*(log(n/Nc)+(n/(sqrt8*Nc))")

+disp("using Ef-Ec = 3* kBT") 

+disp("solving above equation by hit and trial method for n/Nc,we get n/Nc = 4.4") 

+n_by_Nc = 4.4

+n_Si = n_by_Nc*Nc_Si

+disp("carrier density for silicon is n= n_by_Nc*Nc_Si= "+string(n_Si)+"cm^-3")//calculation

+n_GaAs = n_by_Nc*Nc_GaAs

+disp("carrier density for GaAs is n= n_by_Nc*Nc_GaAs= "+string(n_GaAs)+"cm^-3")//calculation

diff --git a/2792/CH2/EX2.2/Ex2_2.sce b/2792/CH2/EX2.2/Ex2_2.sce
new file mode 100755
index 000000000..80fe40f54
--- /dev/null
+++ b/2792/CH2/EX2.2/Ex2_2.sce
@@ -0,0 +1,18 @@
+clc

+mo = 9.1*10^-31

+disp("mo = "+string(mo)+"kg") //initializing value of mass of electron

+ml = 0.98*mo

+disp("ml* = "+string(ml)+"kg") //initializing value of longitudinal mass

+mt = 0.19*mo

+disp("mt*= "+string(mt)+"kg")//initializing value of transverse mass

+mhh =0.49*mo

+disp("mhh* = "+string(mhh)+"kg") //initializing value of heavy hole mass

+mlh = 0.16*mo

+disp("mlh*= "+string(mlh)+"kg")//initializing value of light hole mass

+mdos = (((6)^(2/3))*((ml)*((mt)^2))^(1/3))

+disp("The conduction band density of states mass is ,(mdos* = (((6)^(2/3))*((ml*)*((mt*)^2))^(1/3)))= "+string(mdos)+"kg")//calculation

+mdos1 = (((mhh)^(3/2)+(mlh)^(3/2))^(2/3))

+disp("The Valence band density of states mass is ,(mdos1* = (((mhh)^(3/2)+(mlh)^(3/2))^(2/3))= "+string(mdos1)+"kg")//calculation

+

+ 

+

diff --git a/2792/CH2/EX2.3/Ex2_3.sce b/2792/CH2/EX2.3/Ex2_3.sce
new file mode 100755
index 000000000..e631c7254
--- /dev/null
+++ b/2792/CH2/EX2.3/Ex2_3.sce
@@ -0,0 +1,23 @@
+clc

+h=1.05*10^-34

+disp("h = "+string(h)+"Js") //initializing value of reduced plancks constant or dirac constant or h-bar

+mo = 9.1*10^-31

+disp("mo = "+string(mo)+"kg") //initializing value of mass of electron

+mhh =0.5*mo

+disp("m* = "+string(mhh)+"kg") //initializing value of heavy hole mass

+k = 0.1*10^10

+disp("k = "+string(k)+"m^-1") //initializing value of k-value in the heavy hole band of semiconductor

+Ev = 0

+disp("Ev= "+string(Ev)+"J")//initializing value of Energy of electron in valence band

+e = 1.6*10^-19

+disp("e= "+string(e)+"C")//initializing value of charge of electron

+//(we have assumed the valence band energy Ev=0eV as it is not provided in the book)

+Ee= Ev-(((h^2)*(k^2))/(2*mhh))

+disp("The electron energy in the valence band is ,(Ee= Ev-(((h^2)*(k^2))/(2*mhh))= "+string(Ee)+"J")//calculation

+Ee1= Ee/e

+disp("The electron energy in the valence band is ,Ee= Ee/e="+string(Ee1)+"eV")//calculation

+Eh= Ev+((((h^2)*(k^2))/(2*mhh))/e)

+disp("The hole energy in the valence band is ,(Eh= Ev+((((h^2)*(k^2))/(2*mhh))/e)= "+string(Eh)+"eV")//calculation

+

+ 

+

diff --git a/2792/CH2/EX2.4/Ex2_4.sce b/2792/CH2/EX2.4/Ex2_4.sce
new file mode 100755
index 000000000..1c766c668
--- /dev/null
+++ b/2792/CH2/EX2.4/Ex2_4.sce
@@ -0,0 +1,18 @@
+clc

+h=1.05*10^-34

+disp("h = "+string(h)+"Js") //initializing value of reduced plancks constant or dirac constant or h-bar

+mo = 9.1*10^-31

+disp("mo = "+string(mo)+"kg") //initializing value of mass of electron

+m = 0.067*mo

+disp("m = "+string(m)+"kg") //initializing value of heavy hole mass

+E = 0.5*1.6*10^-19

+disp("E = "+string(E)+"J") //initializing value of electron energy measured from the bandedge

+//  Effective momentum of electron in the conduction band of GaAs

+hk = sqrt(2*m*E)

+disp("The effetive momentum of an electron in the conduction band of GaAs is ,hk = sqrt(2*m*E)= "+string(hk)+"m^-1")//calculation

+k = hk/h

+disp("the corresponding wavevector is,k = hk/h = "+string(k)+"m^-1") //calculation

+//Effective momentum of free electron in the space with same energy

+p = sqrt(2*mo*E)

+disp("The effetive momentum of an electron in the space is ,p = sqrt(2*mo*E)= "+string(p)+"kgms^-1")//calculation

+

diff --git a/2792/CH2/EX2.5/Ex2_5.sce b/2792/CH2/EX2.5/Ex2_5.sce
new file mode 100755
index 000000000..535960307
--- /dev/null
+++ b/2792/CH2/EX2.5/Ex2_5.sce
@@ -0,0 +1,29 @@
+clc

+h=1.05*10^-34

+disp("h = "+string(h)+"Js") //initializing value of reduced plancks constant or dirac constant or h-bar

+mo = 9.1*10^-31

+disp("mo = "+string(mo)+"kg") //initializing value of mass of electron

+ml = 0.98*mo

+disp("ml* = "+string(ml)+"kg") //initializing value of longitudinal mass

+mt = 0.19*mo

+disp("mt*= "+string(mt)+"kg")//initializing value of transverse mass

+a = 5.43*10^-10

+disp("a = "+string(a)+"J") //initializing value of latice constant

+kx = ((2*%pi*0.95)/a)

+disp("kx = "+string(kx)+"m^-1") //initializing value of given k-value in x direction 

+ky = ((2*%pi*0.1)/a)

+disp("ky = "+string(ky)+"m^-1") //initializing value of given k-value in y direction 

+kz = ((2*%pi*0.0)/a)

+disp("kz = "+string(kz)+"m^-1") //initializing value of given k-value in z direction 

+kxo = ((2*%pi*0.85)/a)

+disp("kxo = "+string(kxo)+"m^-1") //initializing value of k-value for Si occupies the (100) valley in x direction 

+kyo = ((2*%pi*0.0)/a)

+disp("kyo = "+string(kyo)+"m^-1") //initializing value of k-value for Si occupies the (100) valley in y direction 

+kzo = ((2*%pi*0.0)/a)

+disp("kzo = "+string(kzo)+"m^-1") //initializing value of k-value for Si occupies the (100) valley in z direction 

+kl = kx-kxo

+disp("the change in k vector in x direction is,kl = kx-kxo = "+string(kl)+"m^-1") //calculation

+kt = ky-kyo

+disp("the change in k vector in y direction is,kt = ky-kyo = "+string(kt)+"m^-1") //calculation

+E= (((h^2)*(kl^2))/(2*ml))+(((h^2)*(kt^2))/(2*mt))

+disp("The electron energy measured from the conduction bandege is ,E= (((h^2)*(kl^2))/(2*ml))+(((h^2)*(kt^2))/(2*mt))= "+string(E)+"J")//calculation

diff --git a/2792/CH2/EX2.9/Ex2_9.sce b/2792/CH2/EX2.9/Ex2_9.sce
new file mode 100755
index 000000000..a12aa7b5d
--- /dev/null
+++ b/2792/CH2/EX2.9/Ex2_9.sce
@@ -0,0 +1,35 @@
+clc

+h=1.05*10^-34

+disp("h = "+string(h)+"Js") //initializing value of reduced plancks constant or dirac constant or h-bar

+mo = 9.1*10^-31

+disp("mo = "+string(mo)+"kg") //initializing value of mass of electron

+me = 0.067*mo

+disp("me* = "+string(me)+"kg") //initializing value of effective mass of GaAs

+kbT = 4.16*10^-21

+disp("kbT = "+string(kbT)+"J/K") //initializing value of kbT at 300K

+Nc=2*(((me*kbT)/(2*%pi*(h^2)))^(3/2))

+disp("for GaAs conduction band case effective density of states is ,Nc = 2*(((me*kbT)/(2*%pi*(h^2)))^(3/2)) = "+string(Nc)+"m^-3")//calculation

+ml = 0.98*mo

+disp("ml* = "+string(ml)+"kg") //initializing value of longitudinal mass

+mt = 0.19*mo

+disp("mt*= "+string(mt)+"kg")//initializing value of transverse mass

+mdos = (((6)^(2/3))*((ml)*((mt)^2))^(1/3))

+disp("The conduction band density of states mass is (mdos* = (((6)^(2/3))*((ml*)*((mt*)^2))^(1/3)))= "+string(mdos)+"kg")//calculation

+Nc1 = 2*((mdos*kbT)/(2*(%pi)*(h^2)))^(3/2)

+disp("for silicon conduction band case effective density of states is ,Nc = 2*((mdos*kbT)/(2*(%pi)*(h^2)))^(3/2) = "+string(Nc1)+"m^-3")//calculation

+// Note : due to different precisions taken by me and the author ... my answer differ 

+disp("          for silicon                 ")

+mhh =0.5*mo

+disp("mhh* = "+string(mhh)+"kg") //initializing value of heavy hole mass for silicon

+mlh = 0.15*mo

+disp("mlh*= "+string(mlh)+"kg")//initializing value of light hole mass for silicon

+Nv1 =((kbT/(2*(%pi)*(h^2)))^(3/2))*2*(mhh^(3/2)+mlh^(3/2))

+disp("for silicon valence band case effective density of states is ,Nv = 2*(mhh^(3/2)+mlh^(3/2))*(kbT/(2*(%pi)*(h^2)))^(3/2)= "+string(Nv1)+"m^-3")//calculation

+disp("for GaAs ")

+mhh1 =0.45*mo

+disp("mhh* = "+string(mhh1)+"kg") //initializing value of heavy hole mass

+mlh1 = 0.08*mo

+disp("mlh*= "+string(mlh1)+"kg")//initializing value of light hole mass

+Nv = 2*(mhh1^(3/2)+mlh1^(3/2))*((kbT/(2*(%pi)*(h^2)))^(3/2))

+disp("for GaAs valence band case effective density of states is ,Nv = 2*(mhh1^(3/2)+mlh1^(3/2))*(kbT/(2*(%pi)*(h^2)))^(3/2)= "+string(Nv)+"m^-3")//calculation

+// Answer given in the book for valence band case is wrong