{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter2 : Energy Bands and Charge Carriers in semiconductor" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.1 Page No.58" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "dE1=0.1 #eV\n", "dE2=-0.1 #eV\n", "k=8.61*10**-5 #Boltzman constant\n", "T=300 #K\n", "\n", "import math\n", "FE1=1/(1+math.exp(dE1/(k*T)))\n", "FE2=1/(1+math.exp(dE2/(k*T)))\n", "\n", "print\"Probability when the energy of the state is above 0.1 eV\",round(FE1,2)\n", "print\"Probability when the energy of the state is below 0.1 eV\",round(FE2,2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Probability when the energy of the state is above 0.1 eV 0.02\n", "Probability when the energy of the state is below 0.1 eV 0.98\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.2 Page No. 58" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "Ef=6.25 #EV fermi energy level\n", "dE=-0.30 #eV\n", "k=8.61*10**-5 #Boltzman constant\n", "fE=0.99\n", "\n", "T=(dE)/(k*math.log(1/fE-1))\n", "\n", "print\"The Temprature is\",round(T,1),\"K\" " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Temprature is 758.3 K\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.3 Page No. 64" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "Eg=0.72 #eV\n", "Ef=0.5*Eg\n", "dE=Eg-Ef #eV\n", "k=8.61*10**-5 #Boltzman constant\n", "T=300 #K\n", "\n", "import math\n", "N=1/(1+math.exp(dE/(k*T)))\n", "\n", "\n", "print\"the fraction of total no. of electron is \",round(N,9)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the fraction of total no. of electron is 8.85e-07\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.4 Page No. 64" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "E=300*1.602*10**-19 #eV Energy\n", "m=9.108*10**-31 #kg, mass of electron\n", "h=6.626*10**-34 #Planck constant\n", "\n", "v=math.sqrt(2*E/m)\n", "lam=h*v/E\n", "\n", "print\"The wavwlength is\",round(lam*10**10,3),\"A\"\n", "\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The wavwlength is 1.416 A\n" ] } ], "prompt_number": 22 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.5 Page No. 70" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "ni=1.4*10**18\t\t\t#in atoms/m**3\n", "Nd=1.4*10**24\t\t\t#in atoms/m**3\n", "n=Nd\t\t\t\t#in atoms/m**3\n", "\n", "p=ni**2/n\t\t\t#in atoms/m**3\n", "ratio=n/p\t\t\t#unitless\n", "\n", "print\"Ratio of electron to hole concentration : \",round(ratio,2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Ratio of electron to hole concentration : 1e+12\n" ] } ], "prompt_number": 25 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.7 Page no 74" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "n=10**24 #Electron density\n", "e=1.6*10**-19 #Electron charge\n", "v=0.015 #m/s drift velocity\n", "A=10**-4 #m**2 area\n", "\n", "I=n*e*v/A\n", "\n", "print\"The magnitude of current is\",round(I/10**8,2),\"A\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The magnitude of current is 0.24 A\n" ] } ], "prompt_number": 35 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.8 Page No. 74" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "Ef=5.5\t\t\t#in eV\n", "MUe=7.04*10**-3\t\t#in m**2/V-s\n", "n=5.8*10**28\t\t#in m**-3\n", "e=1.6*10**-19\t\t#constant\n", "m=9.1*10**-31\t\t#in Kg\n", "\n", "import math\n", "tau=MUe*m/e\t\t#in sec\n", "rho=1/(n*e*MUe)\t\t#in ohm-m\n", "vF=math.sqrt(2*Ef*1.6*10**-19/m)\n", "\n", "print\"Relaxation time in sec : \",tau,\"s\"\n", "print\"Resistivity of conductor in ohm-m : \",round(rho,11),\"ohm m\"\n", "print\"velocity of electron with fermi energy is \",round(vF,0),\"m/s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Relaxation time in sec : 4.004e-14 s\n", "Resistivity of conductor in ohm-m : 1.531e-08 ohm m\n", "velocity of electron with fermi energy is 1390707.0 m/s\n" ] } ], "prompt_number": 32 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.9 Page No. 75" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "rho=1.73*10**-8 #resistivity\n", "Tav=2.42*10**-14 #Average Time\n", "e=1.6*10**-19\t\t#constant\n", "m=9.1*10**-31\t\t#in Kg\n", "\n", "n=m/(e**2*Tav*rho)\n", "mu=(e*Tav)/m\n", "\n", "print\"NO. of free electrons are\",round(n,-26)\n", "print\"mobility of electrons is\",round(mu,3),\"m**2/Vs\"\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "NO. of free electrons are 8.49e+28\n", "mobility of electrons is 0.004 m**2/Vs\n" ] } ], "prompt_number": 51 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.10 page No. 75" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "Ef=100\t\t\t#in V/m Applied electric field\n", "n=6*10**28\t\t#in m**-3\n", "e=1.6*10**-19\t\t#constant electronic charge\n", "m=9.1*10**-31\t\t#in Kg mass of electron\n", "rho=1.5*10**-8 #Density\n", "\n", "import math\n", "tau=m/(n*e**2*rho)\t\t#in sec\n", "vF=e*Ef*tau/m\n", "\n", "print\"Relaxation time in sec : \",round(tau,16),\"s\"\n", "print\"velocity of electron with fermi energy is \",round(vF,1),\"m/s\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Relaxation time in sec : 3.95e-14 s\n", "velocity of electron with fermi energy is 0.7 m/s\n" ] } ], "prompt_number": 57 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.11 Page No.75" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "d=0.002 #m, diameter of pipe\n", "s=5.8*10**7 #Conductivity S/m\n", "mu=0.0032 #m**2/Vs, Electron mobility\n", "e=1.6*10**-19\t\t#constant electronic charge\n", "m=9.1*10**-31\t\t#in Kg mass of electron\n", "E=0.02 #V/m Electric field\n", "\n", "import math\n", "n=s/(e*mu)\n", "J=s*E\n", "I=J*(math.pi*d**2/4.0)\n", "v=mu*E\n", "\n", "print\"Charge density is\",round(n,-26),\"m**-3\"\n", "print\"current density is\",round(J,6),\"A/m**2\"\n", "print\"curret flowing is\",round(I,3),\"A\"\n", "print\"electron drift velocityis\",round(v,6),\"m/s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Charge density is 1.133e+29 m**-3\n", "current density is 1160000.0 A/m**2\n", "curret flowing is 3.644 A\n", "electron drift velocityis 6.4e-05 m/s\n" ] } ], "prompt_number": 69 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.12 page no 76" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "rho=0.5 #ohm-m Resistivity\n", "J=100 #A/m**2 Current density\n", "mue=0.4 #m**2/Vs Electron mobility\n", "d=10*10**-6 #m distance\n", "\n", "Ve=mue*J*rho\n", "t=d/Ve\n", "\n", "print\"The drift velocity is \",Ve,\"m/s\"\n", "print\"Time taken by the electron is\",round(t,8),\"s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The drift velocity is 20.0 m/s\n", "Time taken by the electron is 5e-07 s\n" ] } ], "prompt_number": 156 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.13 Page No.76" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "e=1.6*10**-19\t\t#constant electronic charge\n", "m=9.1*10**-31\t\t#in Kg mass of electron\n", "rho=0.039 #ohm-cm resistivity\n", "mu=3600 #cm**2/Vs Carrier mobility\n", "ni=2.5*10**13\n", "\n", "Nd=(1/(rho*e*mu))\n", "n=Nd\n", "p=(ni**2/n)\n", "\n", "print\"Concentration of electron is\",round(n,-14),\"/cm**3\"\n", "print\"Concentration of holes is\",round(p,0),\"/cm**3\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Concentration of electron is 4.45e+16 /cm**3\n", "Concentration of holes is 14040000000.0 /cm**3\n" ] } ], "prompt_number": 76 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.14 page No 76" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "rho=5.32 #kg/m**3, density\n", "Aw=72.6 #kg/K kmol atomic weight\n", "ni=2.5*10**13\n", "di=10**8 #Donor impurity\n", "e=1.6*10**-19 #Electronic charge\n", "mue=0.38 #m**/Vs\n", "muh=0.18 #m**/Vs\n", "\n", "N=6.023*10**23*rho/Aw #No 0f germanium atoms per cm**3\n", "Nd=N/di\n", "n=Nd\n", "p=(ni**2/n)\n", "s=n*e*mue*10**4\n", "\n", "print\"Concentration of electrons is\",round(n,-12),\"atoms/cm**3\"\n", "print\"Concentration of holes is\",round(p,-10),\"atoms/cm**3\"\n", "\n", "if n > p:\n", " \n", " print\"Conductivity of N-type germanium\",round(s*100,1),\"/ohm-m\" \n", "else:\n", " print \"Calculate p-type germanium conductivity\"\n", "\n", "\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Concentration of electrons is 4.41e+14 atoms/cm**3\n", "Concentration of holes is 1.42e+12 atoms/cm**3\n", "Conductivity of N-type germanium 26.8 /ohm-m\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.15 Page no.79" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "e=1.6*10**-19 #Electronic charge\n", "mue=0.39 #m**/Vs\n", "muh=0.19 #m**/Vs\n", "rhoi=0.47 #ohm-m, intrinsic resistivity\n", "E=10**4 #Electric field\n", "\n", "sigmai=1/rhoi\n", "ni=sigmai/(e*(mue+muh))\n", "Vn=mue*E\n", "Vh=muh*E\n", "\n", "print\"Density of electrons is\",round(ni,-17),\"/m**3\"\n", "print\"Drift velocity for electrons\",round(Vn,0),\"m/s\"\n", "print\"Drift velocity for holes\",round(Vh,0),\"m/s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Density of electrons is 2.29e+19 /m**3\n", "Drift velocity for electrons 3900.0 m/s\n", "Drift velocity for holes 1900.0 m/s\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.16 page No.80" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "i=10**7 #IMpurity in Ge atom\n", "ni=2.5*10**13 #/cm**3\n", "N=4.4*10**22 #No. of atoms of Ge\n", "mue=3800 #cm**2/Vs\n", "muh=1800 #cm**2/Vs\n", "e=1.6*10**-19 #Electronic charge\n", "E=400 #Electric field\n", "\n", "sigmai=ni*e*(mue+muh)\n", "Nd=N/i\n", "n=Nd\n", "p=ni**2/(Nd)\n", "sigman=e*Nd*mue\n", "\n", "print\"Intrinsic conductivity of Ge is \",sigmai,\"ohm-cm**-1\"\n", "print\"Conductivity of N type Ge semiconductor is\",round(sigman,2),\"ohm-cm**-1\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Intrinsic conductivity of Ge is 0.0224 ohm-cm**-1\n", "Conductivity of N type Ge semiconductor is 2.68 ohm-cm**-1\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.17 Page No. 80" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "V=10 #Volt\n", "l=0.025 #m, length\n", "w=0.004 #m width\n", "t=0.0015 #m thickness\n", "\n", "ni=2.5*10**19 #/cm**3\n", "mue=0.38 #m**2/Vs\n", "muh=0.18 #m**2/Vs\n", "e=1.6*10**-19 #Electronic charge\n", "E=400 #Electric field\n", "\n", "E=V/l\n", "Ve=mue*E\n", "Vh=muh*E\n", "sigmai=ni*e*(mue+muh)\n", "I=sigmai*E*w*t\n", "\n", "print\"(i)Electron drift velocity is \",Ve,\"m/s\"\n", "print\" hole drift velocity is \",Vh,\"m/s\"\n", "print\"(ii)Intrinsic Conductivity of Ge is\",sigmai,\"ohm-m**-1\"\n", "print\"(iii)The total current is \",I*1000,\"mA\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(i)Electron drift velocity is 152.0 m/s\n", " hole drift velocity is 72.0 m/s\n", "(ii)Intrinsic Conductivity of Ge is 2.24 ohm-m**-1\n", "(iii)The total current is 5.376 mA\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.18 page no.80" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "Ie=3/4.0 #Current due to electron\n", "Ih=1-Ie #Current due to holes\n", "Vh=1 #Hole velocity\n", "Ve=3 #Electron velocity 3 times the hole velocity\n", "\n", "R=(Ie*Vh/(Ih*Ve))\n", "\n", "print\"The ratio of electrons to holes drift velocity is \",R" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The ratio of electrons to holes drift velocity is 1.0\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.19 Page No.81" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "e=1.6*10**-19\t\t\t#in coulamb\n", "T=300\t\t\t\t#in Kelvin\n", "MUh=0.025\t\t\t#in m**2/V-s\n", "MUe=0.17\t\t\t#in m**2/V-s\n", "k=1.38*10**-23\t\t\t#in J/K\n", "De=MUe*k*T/e\t\t\t#in cm**2/s\n", "Dh=MUh*k*T/e\t\t\t#in cm**2/s\n", "\n", "print\"Diffusion constant of electron is \",round(De*10000,2),\"(in cm**2/s)\"\n", "print\"Diffusion constant of hole is \",round(Dh*10000,2),\"(in cm**2/s)\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Diffusion constant of electron is 43.99 (in cm**2/s)\n", "Diffusion constant of hole is 6.47 (in cm**2/s)\n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.20 Page no. 81 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "N=3*10**25 #No of atoms\n", "e=1.6*10**-19\n", "Eg=1.1*e #eV\n", "k=1.38*10**-23 #j/k boltzman's constant\n", "T=300 #K\n", "mue=0.14\n", "muh=0.05\n", "\n", "ni=N*math.exp(-Eg/(2*k*T))\n", "sigma=ni*e*(mue+muh)\n", "\n", "print\"The intrinsic carries concentration is \",round(ni,-14),\"/m**3\"\n", "print\"The conductivity of Si is \",round(sigma,5),\"S/m\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The intrinsic carries concentration is 1.76e+16 /m**3\n", "The conductivity of Si is 0.00054 S/m\n" ] } ], "prompt_number": 40 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.21 Page No.84" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "a=1.5 #a=me/mo\n", "T=300 #K\n", "\n", "Nc=4.82*10**21*(a)**(1.5)*T**(1.5)\n", "\n", "print\"The effective density is\",round(Nc,-23),\"/m**3\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The effective density is 4.6e+25 /m**3\n" ] } ], "prompt_number": 44 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.22 page no. 84" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "a=0.07 #a=me/mo\n", "b=0.4 #b=mh/mo\n", "T=300 #K\n", "Eg=0.7 #eV\n", "k=8.62*10**-5 # Boltzman constant\n", "\n", "import math\n", "ni=math.sqrt(2.33*10**43*(a*b)**(1.5)*T**3*math.exp(-Eg/(k*T)))\n", "\n", "print\"The intrinsic concentration of charge carrier is\",round(ni,-16),\"/m**3\"\n", "\n", "\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The intrinsic concentration of charge carrier is 2.27e+18 /m**3\n" ] } ], "prompt_number": 55 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.23 Page no. 85" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "C=5*10**28 #atom/m**3, concentration of Si atoms\n", "DL=2*10**8 #Doping level \n", "m=1\n", "me=m\n", "Nd=C/DL\n", "nc=Nd\n", "T=((nc/(4.82*10**21))*(m/me)**(1.5))**(2/3.0)\n", "\n", "print\"The absolute temprature is\",round(T,2),\"K\"\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The absolute temprature is 0.14 K\n" ] } ], "prompt_number": 61 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.24 Page No. 85" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "T1=300.0 #K temprature\n", "T2=400.0\n", "k=1.38*10**-23 #J/k\n", "m=1.25*9.107*10**-31\n", "h=6.625*10**-34\n", "dE=0.3 #eV\n", "k_=8.62*10**-5\n", "\n", "import math\n", "nc1=2*(2*math.pi*m*k*T1/(h**2))**(1.5)\n", "n1=nc1*math.exp(-(0.3/(k_*T1)))\n", "\n", "nc2=2*(2*math.pi*m*k*T2/(h**2))**(1.5)\n", "n2=nc2*math.exp(-(0.3/(k_*T2)))\n", "\n", "print\"The effective density at temprature 300 K is\",round(n1,-19),\"/m**3\"\n", "print\"The effective density at temprature 400 K is\",round(n2,-19),\"/m**3\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The effective density at temprature 300 K is 3.2e+20 /m**3\n", "The effective density at temprature 400 K is 8.98e+21 /m**3\n" ] } ], "prompt_number": 110 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.25 Page no.86" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "T=300.0\n", "k=8.62*10**-5 #J/k\n", "m=9.107*10**-31\n", "me=0.6*m\n", "mh=0.4*m\n", "\n", "\n", "dE=-3*k*T*math.log((me/mh)**(1))/4.0 #dE=Ef-Emidgap\n", "\n", "print\"The position of fermi level is\",round(dE,4),\"eV\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The position of fermi level is -0.0079 eV\n" ] } ], "prompt_number": 116 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.26 Page no 86" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "T=300.0\n", "Eg=0.72 #eV Energy gap\n", "k=8.62*10**-5 #J/k\n", "me=1\n", "mh=5.0\n", "\n", "import math\n", "dE=(Eg/2.0)-3*k*T*math.log(me/mh)/4.0 #dE=Ef-Emidgap\n", "\n", "print\"The position of fermi level is\",round(dE,4),\"eV\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The position of fermi level is 0.3912 eV\n" ] } ], "prompt_number": 131 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.27 Page no 87" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "T1=300.0\n", "T2=350\n", "Eg=0.24 #eV Energy gap\n", "\n", "import math\n", "dE=(T2/T1)*Eg\n", "\n", "print\"The position of fermi level is\",round(dE,4),\"eV\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The position of fermi level is 0.28 eV\n" ] } ], "prompt_number": 134 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.28 Page no.88" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "T1=300.0\n", "T2=400\n", "Eg=0.27 #eV Energy gap\n", "\n", "import math\n", "dE=(T2/T1)*Eg\n", "\n", "print\"The position of fermi level is\",round(dE,4),\"eV\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The position of fermi level is 0.36 eV\n" ] } ], "prompt_number": 133 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.29 page no.88" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "dE1=0.3 #eV Energy gap\n", "kT=0.026 #eV\n", "\n", "import math\n", "x=math.exp(-dE1/kT) #x=Nd/nc\n", "y=5 #y=Nd2/Nd1\n", "dE2=-math.log(y)*kT+dE1\n", "\n", "print\"The position of fermi level is\",round(dE2,3),\"eV\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The position of fermi level is 0.258 eV\n" ] } ], "prompt_number": 137 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.30 Page no.89" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "dE1=0.39 #eV Energy gap\n", "kT=0.026 #eV\n", "\n", "import math\n", "x=math.exp(-dE1/kT) #x=NA1/nV\n", "y=3 #y=NA2/NA1\n", "dE2=((dE1/kT)-math.log(y))*kT\n", "\n", "\n", "print\"The position of fermi level is\",round(dE2,2),\"eV\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The position of fermi level is 0.36 eV\n" ] } ], "prompt_number": 143 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.31 Page no.91" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "rho=1 #ohm-m Resistivity\n", "Rh=100.0 #cm**3/coulomb\n", "e=1.6*10**-19\n", "\n", "con=1/rho #Conductivity\n", "R=1/Rh #Charge density\n", "ED=R*10**6/e\n", "mu=con/(R*10**6)\n", "\n", "print\"The electron density is\",ED,\"/m**3\"\n", "print\"The mobility is %.e\"%mu,\"/m**3\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The electron density is 6.25e+22 /m**3\n", "The mobility is 1e-04 /m**3\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.32 Page no. 92" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "w=0.1 #m width\n", "t=0.01 #m thickness\n", "F=0.6 #T, field\n", "Rh=3.8*10**-4 #Hall Coefficient\n", "I=10 #mA\n", "\n", "Vh=(Rh*F*I/w)\n", "\n", "print\"Hall Voltage is\",Vh*1000,\"micro V\"\n", "\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Hall Voltage is 22.8 micro V\n" ] } ], "prompt_number": 146 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.33 Page No. 92" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "e=1.6*10**-19\t\t\t#in coulamb\n", "ND=10**17\t\t\t#in cm**-3\n", "Bz=0.1\t\t\t\t#in Wb/m**2\n", "w=4\t\t\t\t#in mm\n", "d=4\t\t\t\t#in mm\n", "Ex=5\t\t\t\t#in V/cm\n", "MUe=3800\t\t\t#in cm**2/V-s\n", "\n", "v=MUe*Ex\t\t\t#in cm/s\n", "v=v*10**-2\t\t\t#in m/s\n", "VH=Bz*v*d\t\t\t#in mV\n", "\n", "print\"Magnitude of hall voltage is\",VH,\"mV\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Magnitude of hall voltage is 76.0 mV\n" ] } ], "prompt_number": 19 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.34 Page No.92" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "e=1.6*10**-19\t\t\t#in coulamb\n", "ND=10**21\t\t\t#in m**-3\n", "Bz=0.2\t\t\t\t#in T\n", "d=4\t\t\t\t#in mm\n", "d=d*10**-3\t\t\t#in meter\n", "J=600\t\t\t\t#in A/m**2\n", "n=ND\t\t\t\t#in m**-3\n", "\n", "VH=Bz*J*d/(n*e)\t\t\t#in V\n", "\n", "print\"Magnitude of hall voltage is \",VH*10**3,\"mV\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Magnitude of hall voltage is 3.0 mV\n" ] } ], "prompt_number": 22 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 2.35 Page No." ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "e=1.6*10**-19\t\t\t#in coulamb\n", "rho=0.00912\t\t\t#in ohm-m\n", "B=0.48\t\t\t\t#in Wb/m**2\n", "RH=3.55*10**-4\t\t\t#in m**3-coulamb**-1\n", "SIGMA=1/rho\t\t\t#in (ohm=m)**-1\n", "\n", "import math\n", "THETAh=math.atan(SIGMA*B*RH)\t#in Degree\n", "\n", "print\"Hall angle is\",round(THETAh*180/3.14,4),\"degree\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Hall angle is 1.0709 degree\n" ] } ], "prompt_number": 169 }, { "cell_type": "code", "collapsed": false, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }