8 files changed, 174 insertions, 0 deletions
diff --git a/3710/CH7/EX7.1/Ex7_1.sce b/3710/CH7/EX7.1/Ex7_1.sce
new file mode 100644
index 000000000..716940c16
--- /dev/null
+++ b/3710/CH7/EX7.1/Ex7_1.sce
@@ -0,0 +1,13 @@
+//Example 7.1, Page Number 296
+//Detector sensitivity
+clc;
+
+D=10**9 //in meter square root hertz per watt
+l=2*(10**-6) //Wavelength in meter
+A=25*(10**-6) //Area in meter square
+db=10*(10**3) //Detection Bandwidth in hertz
+
+//From equation 7.2
+NEP=(sqrt(A*db))/D //NEP is the detector sensitivty in W
+
+mprintf("The Sensitivty of the device at given wavelength is:%.0e W",NEP)
diff --git a/3710/CH7/EX7.2/Ex7_2.sce b/3710/CH7/EX7.2/Ex7_2.sce
new file mode 100644
index 000000000..1e9f2eae9
--- /dev/null
+++ b/3710/CH7/EX7.2/Ex7_2.sce
@@ -0,0 +1,15 @@
+//Example 7.2, Page Number 306
+//Vacuum photodiode output
+clc;
+
+l=500*(10**-9) //Wavelength of radiation in metres
+P=1*(10**-6) //Power in Watts
+q=0.5 //Quantum Efficiency
+e=1.6*(10**-19) //Charge of an electron in Coulombs
+h=6.63*(10**-34) //Plancks Constant in meter square kilogram per second
+c=3*(10**8) //Speed of light in meters per second
+
+//From equation 7.9
+i=(q*e*P*l)/(h*c) //i is the current generated in Amperes
+
+mprintf("The Current Generated is:%.0e A",i)
diff --git a/3710/CH7/EX7.3/Ex7_3.sce b/3710/CH7/EX7.3/Ex7_3.sce
new file mode 100644
index 000000000..a9ec66e7b
--- /dev/null
+++ b/3710/CH7/EX7.3/Ex7_3.sce
@@ -0,0 +1,37 @@
+//Example 7.3, Page Number 311
+//The Function fpround(dependency) is used to round a floating point number x to n decimal places
+//Minimum detectable signal
+clc;
+
+A=1000*(10**-6) //Cathode Area in metre square
+wf=1.25 //Work function in eV
+T=300 //Cathode temperature in Kelvin
+e=1.6*(10**-19) //Charge of an electron in Coulombs
+k=1.38*(10**-23) //Boltzman Constant in meter square kilogram per second square Kelvin
+a1=1.2*(10**6) //constant for pure metals in Ampere per metre square kelvin square
+l=0.5*(10**-6) //Wavelength in meters
+q=0.25 //Quantum Efficiency
+h=6.63*(10**-34) //Plancks Constant in meter square kilogram per second
+c=3*(10**8) //Speed of light in meters per second
+f=1//bandwidth in hertz
+
+//From equation 7.11
+e1=(k*T)/e 
+e1=fpround(e1,3)
+c2=(-1*wf)/e1
+c2=fpround(c2,4)
+c3=exp(c2)
+it=a1*A*(T**2)*c3 //it is the current generated in Amperes
+
+mprintf("The Thermionic Emission Current is:%.2e A\n",it)
+
+//Using Equation 7.9
+r=(q*e*l)/(h*c) //r is the responsivity in A/W
+r=fpround(r,2)
+mprintf(" The Responsivity is:%0.1f A/W\n",r)
+
+//Using Equation 7.13
+W=(sqrt(2*it*e*f))/r //W is the minimum detectable power in Watts
+mprintf(" The Minimum detectable signal power is:%.3e W",W)
+
+//The answer provided in the textbook is wrong
diff --git a/3710/CH7/EX7.4/Ex7_4.sce b/3710/CH7/EX7.4/Ex7_4.sce
new file mode 100644
index 000000000..7b1f75e0d
--- /dev/null
+++ b/3710/CH7/EX7.4/Ex7_4.sce
@@ -0,0 +1,23 @@
+//Example 7.4, Page Number 311
+//Noise in photomultipliers
+clc;
+
+T=300 //Temperature in Kelvin
+lr=10**3 //Load resistor in ohms
+bw=10**3 //Bandwidth in hertz
+k=1.38*(10**-23) //Boltzman Constant in meter square kilogram per second square Kelvin
+i=10**-14 //Photomultiplier current in Amperes
+e=1.6*(10**-19) //Charge of an electron in Coulombs
+g=10**7 //Photomultiplier Gain
+
+//From equation 7.14
+V=sqrt(4*k*T*bw) //V is the shot noise voltge
+
+//From equation 7.12
+is=sqrt(2*i*e*bw) //is is the shot noise current in Amperes
+
+V1=is*g*lr //V1 is the voltage observed across load resistance
+
+mprintf("The RMS Value of the Voltage is:%.1e V\n",V)
+mprintf(" The Shot Noise Current is:%.1e A\n",is)
+mprintf(" The Shot Noise Voltage across load resistor is:%.1e V",V1)
diff --git a/3710/CH7/EX7.5/Ex7_5.sce b/3710/CH7/EX7.5/Ex7_5.sce
new file mode 100644
index 000000000..610444e22
--- /dev/null
+++ b/3710/CH7/EX7.5/Ex7_5.sce
@@ -0,0 +1,24 @@
+//Example 7.5, Page Number 324
+//The Function fpround(dependency) is used to round a floating point number x to n decimal places
+//Depletion wavelength
+clc;
+
+n3=1//Energy Level
+n2=2//Energy Level
+Lz=10*(10**-9) //Width of the well in metres
+m=9.1*(10**-31) //Mass of an electron in kilogram
+me=0.068*m//effective mass
+h=6.63*(10**-34) //Plancks Constant in meter square kilogram per second
+c=3*(10**8) //Speed of light in meters per second
+e1=1.6*(10**-19) //Charge of an electron in Coulombs
+
+//By Equation 2.64
+
+E=((h**2)/(me*8))*(((n2/Lz)**2)-((n3/Lz)**2)) // E is the energy difference between the levels in eV
+E1=E/e1 //Conversion to electron volt
+E1=fpround(E1,2)
+l=(h*c)/E1 //l is the optical wavelength in metres
+l1=l/e1
+l1=l1*(10**6)
+mprintf("The Energy Difference between the two levels is:%0.3feV\n",E1)
+mprintf(" The Optical Wavelength is:%0.1f um",l1)
diff --git a/3710/CH7/EX7.6/Ex7_6.sce b/3710/CH7/EX7.6/Ex7_6.sce
new file mode 100644
index 000000000..6548c3a5d
--- /dev/null
+++ b/3710/CH7/EX7.6/Ex7_6.sce
@@ -0,0 +1,30 @@
+//Example 7.6, Page Number 329
+//The Function fpround(dependency) is used to round a floating point number x to n decimal places
+//Depletion region thickness
+clc;
+
+//Taking Silicon Diode with moderately doped N-region
+V=100 //Applied Voltage in volts
+Nd=5*(10**21) //in per metre cube
+eo=8.85*(10**-12) //Absolute permittivity in farads per meter
+er=11.7
+e=1.6*(10**-19) //Charge of an electron in Coulombs
+
+//Using equation 7.31
+xn=sqrt((2*eo*er*V)/(e*Nd))
+
+ac=10**5 //Absorption Coefficient per meter
+
+//ignoring Fresnel reflection
+f=1-exp(-1*xn*ac)
+f=fpround(f,3)
+
+disp(xn,"The Depletion region thickness in m:")
+mprintf(" The Fraction of the incident radiation absorbed is: %.1f",f)
+
+//This is insufficient if a high efficiency photodiode is required
+//To absorb 80% of radiation,depletion region thickness has to be 20um wide
+xn=xn*(10**6)//This conversion is done to get the xn value as 5 which is used in the calculation of V1
+t=20
+V1=V*((t/int(xn))**2)
+mprintf("\nHence the required applied voltage is:%d V",V1)
diff --git a/3710/CH7/EX7.7/Ex7_7.sce b/3710/CH7/EX7.7/Ex7_7.sce
new file mode 100644
index 000000000..a615e99c1
--- /dev/null
+++ b/3710/CH7/EX7.7/Ex7_7.sce
@@ -0,0 +1,21 @@
+//Example 7.7, Page Number 334
+//Response time of photodiode
+clc;
+
+it=2*(10**-6) //I-region thickness in metres
+A=(100*(10**-6))*(100*(10**-6)) //Given Area in metres
+lr=50 //Load resistor in ohms
+v=10**5 //Saturation Velocity in Metre/second
+er=12 //relative permittivity of InGaAs
+k=8.85*(10**-12) //Absolute permittivity in farads per meter
+
+t=it/v //Transit Velocity of electrons in m/s
+
+//From equation 7.34
+cj=(A*k*er)/it //cj is the device capacitance in farads
+
+trc=cj*lr //in seconds
+
+total=sqrt((t**2)+(trc**2)) //total is the total response time
+mprintf("The Device Capacitance is:%0.1e F\n",cj)
+mprintf(" The Total response time for the detector is:%.2e s",total)
diff --git a/3710/CH7/EX7.8/Ex7_8.sce b/3710/CH7/EX7.8/Ex7_8.sce
new file mode 100644
index 000000000..17e790ff1
--- /dev/null
+++ b/3710/CH7/EX7.8/Ex7_8.sce
@@ -0,0 +1,11 @@
+//Example 7.8, Page Number 334
+//Diffusion time of carrier
+clc;
+
+t=5*(10**-6) //Thickness of the layer in metres
+Dc=3.4*(10**-3) //Dc is the Minority diffusion coefficient in metre square per second
+
+//From equation 7.37
+td=(t**2)/(2*Dc) //td is the diffusion time in seconds
+
+mprintf("The Time taken for the excess carriers to diffuse is:%.1e s",td)