{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "

Chapter No 2 : Semiconductor Materials and\n", "Their Properties

" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.1, Page No 65 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "lambda1 = 11000.0 #in \u00c5\n", "lambda1 = lambda1 * 10**-10 \n", "h = 6.625*10**-34 \n", "c = 3*10**8\n", "q = 1.6*10**-19 #in C\n", "\n", "#CALCULATIONS\n", "E_g = h*c/lambda1 #in J\n", "E_g= E_g/q #in eV\n", "\n", "#RESULTS\n", "print('The energy gap in Si is = %.2f eV' %E_g)\n", "\n", "#Note: The answer in the book is not correct \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The energy gap in Si is = 1.13 eV\n" ] } ], "prompt_number": 27 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.2, Page No 65 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#initialisation of variables\n", "E_g = 0.75 #in eV\n", "q=1.6*10**-19 #in C\n", "E_g = E_g*q #in J\n", "h = 6.63*10**-34 #in J\n", "c = 3*10**8 #in m/s\n", "\n", "#CALCULATIONS\n", "lembda = (h*c)/E_g #in m\n", "lembda = lembda * 10**10 #in \u00c5\n", "\n", "#RESULTS\n", "print('The wavelength is =%.f \u00c5 ' %lembda)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The wavelength is =16575 \u00c5 \n" ] } ], "prompt_number": 28 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.3 Page No 81 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "from numpy import *\n", "\n", "#initialisation of variables\n", "del_E = 0.3 #value of E_C-E_F in eV\n", "T1 = 330.0 #in K\n", "T = 300 #in K\n", "\n", "#CALCULATIONS\n", "del_E1 = del_E*(T1/T) #value of E_C-E_F in eV\n", "\n", "#RESULTS\n", "print('The position of fermi level is =%.2f eV' %del_E1)\n", "print('Hence the Fermi level will be %.2f eV below the conduction band' %del_E1)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The position of fermi level is =0.33 eV\n", "Hence the Fermi level will be 0.33 eV below the conduction band\n" ] } ], "prompt_number": 29 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.4, Page No 81" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#initialisation of variables\n", "K = 8.63*10**-5\n", "T = 300.0 #in K\n", "N_C = 2.8*10**19 #in cm^-3\n", "del_E = 0.25\n", "\n", "#CALCULATIONS\n", "f_F = math.exp( (-del_E)/(K*T) )\n", "n_o = N_C*math.exp( (-del_E)/(K*T) ) #in cm^-3\n", "\n", "#RESULTS\n", "print('The probability is =%.6f ' %f_F)\n", "print('The thermal equillibrium electron concentration is =%.2f X 10^15 cm^-3' %(n_o/(10**15)))\n", "print('Approximation error ')\n", "# The answer is same as in book only thy have rounded off to 1.8 * 10^15 which is same as above" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The probability is =0.000064 \n", "The thermal equillibrium electron concentration is =1.79 X 10^15 cm^-3\n", "Approximation error \n" ] } ], "prompt_number": 30 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.5 Page No 82" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#initialisation of variables\n", "N_V = 1.04*10**19 #in cm^-3\n", "T1 = 400.0 #in K\n", "T2 = 300.0 #in K\n", "del_E = 0.27 #value of E_F-E_V in eV\n", "K = 0.0259\n", "\n", "#CALCULATIONS\n", "N_V= N_V*(T1/T2)**(3/2) #in cm^-3\n", "KT = K*(T1/T2) #in eV\n", "p_o = N_V*math.exp( (-del_E)/(KT) ) #in /cm^3\n", "\n", "#RESULTS\n", "print('The hole concentration is =%.2f x 10^15 per cm^3' %(p_o/(10**15)))\n", "print('Approximationa error ')" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The hole concentration is =5.58 x 10^15 per cm^3\n", "Approximationa error \n" ] } ], "prompt_number": 31 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.6 Page No 86" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#initialisation of variables\n", "N = 6.02*10**23\n", "A = 63.5 #atomic weight\n", "Rho = 1.7*10**-6 #in ohm cm\n", "d = 8.96 # in gm/cc\n", "\n", "#CALCULATIONS\n", "n = (N/A)*d #in /cc\n", "e = 1.6*10**-19 #in C\n", "Miu_e = 1/(Rho*n*e) #in cm^2/volt-sec\n", "\n", "#RESULTS\n", "print('The mobility of electron is =%.2f cm^2/volt.sec' %Miu_e)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The mobility of electron is =43.28 cm^2/volt.sec\n" ] } ], "prompt_number": 32 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.7, Page No 87" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "from sympy.mpmath import *\n", "import cmath\n", "\n", "\n", "#initialisation of variables\n", "d = 8.96 #in gm/cc\n", "At = 63.5 #atomic weight\n", "N_A = 6.02*10**23 #in /gm mole\n", "l = 0.1 #in m\n", "e = 1.6*10**-19 #in C\n", "A = 1.7*10**-6 #in m^2\n", "R = 0.1 #in ohm\n", "\n", "#CALCULATIONS\n", "n = (N_A/At)*d #in /cc\n", "n = n * 10**6 #in /m^3\n", "Rho = (R*A)/l #in ohm.m\n", "Sigma = 1/Rho #in mho/m\n", "Miu_e = Sigma/(n*e) #in m^2/V-sec\n", "\n", "#RESULTS\n", "print('The electron mobility is =%.3f X 10^-3 m^2/V-sec ' %(Miu_e*(10**3)))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The electron mobility is =0.043 X 10^-3 m^2/V-sec \n" ] } ], "prompt_number": 33 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.8 Page No 87" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "#initialisation of variables\n", "N_A = 6.025*10**23 #in /gm mole\n", "d = 10.5 #in gm/cc\n", "At = 108.0 #atomic weight of \n", "\n", "#CALCULATIONS\n", "n = (N_A/At)*d #in /cm^3\n", "n = n * 10**6 #in /m^3\n", "r = 10**-3 #in m\n", "A = math.pi * ((r)**2) #in m^2\n", "q = 1.6*10**-19 \n", "I = 2 #in A\n", "V = I/(n*q*A) #in m/s\n", "\n", "#RESULTS\n", "print('The drift velocity of an electron is =%.f X 10^-4 m/s' %(V*(10**5)))\n", "print('Approximationa error ')\n", "# answer is same as in book only they have rounded of 0.000068 to 7 * 10^-4" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The drift velocity of an electron is =7 X 10^-4 m/s\n", "Approximationa error \n" ] } ], "prompt_number": 34 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.9 Page No 88" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#initialisation of variables\n", "e= 1.6*10**-19 #in C\n", "d= 1.03 #in mm\n", "d= d*10**-3 #in m\n", "R= 6.51 #in ohm\n", "l= 300.0 #in m\n", "n= 8.4*10**28 #per m^3\n", "\n", "#CALCULATIONS\n", "r= d/2 #in m (radius)\n", "A= math.pi*r**2 #in m^2\n", "rho= R*A/l #in ohm meter\n", "sigma= 1/rho #in mho/m\n", "miu_e= sigma/(n*e) #m^2/V-sec\n", "\n", "#RESULTS\n", "print('The coductivity of copper is =%.2f mho/m' %sigma)\n", "print('The mobility of charge carriers is : =%.6f m^2/V-sec' %miu_e)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The coductivity of copper is =55306469.41 mho/m\n", "The mobility of charge carriers is : =0.004115 m^2/V-sec\n" ] } ], "prompt_number": 35 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.9.ii Page No 88" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#initialisation of variables\n", "Miu_e = 1500.0 #in cm^2/volt.sec\n", "Miu_h = 500.0 #in cm^2/volt.sec\n", "n_i = 1.6*10**10 #in /cm^3\n", "e = 1.6*10**-19 #in C\n", "\n", "#CALCULATIONS\n", "Sigma_i = n_i*(Miu_e+Miu_h)*e #in mho/cm\n", "Sigma = Sigma_i #in mho/cm\n", "\n", "#RESULTS\n", "print('The conductivity of pure silicon is =%.7f mho/cm' %Sigma)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The conductivity of pure silicon is =0.0000051 mho/cm\n" ] } ], "prompt_number": 36 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example No 2.10 Page No 89" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "Miu_e = 1500.0 #in cm^2/volt.sec\n", "Miu_h = 500.0 #in cm^2/volt.sec\n", "n_i = 1.6*10**10 #in /cm^3\n", "e = 1.6*10**-19 #in C\n", "\n", "#CALCULATIONS\n", "Sigma_i = n_i*(Miu_e+Miu_h)*e #in mho/cm\n", "Sigma = Sigma_i #in mho/cm\n", "\n", "#RESULTS\n", "print('The conductivity of pure silicon is =%.2f X 10^-6 mho/cm' %(Sigma*(10**6)))\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The conductivity of pure silicon is =5.12 X 10^-6 mho/cm\n" ] } ], "prompt_number": 37 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example No 2.11 Page No 90" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "Miu_d = 500.0 #in cm^2/V.S\n", "Rho = 10 #in ohm cm \n", "\n", "#CALCULATIONS\n", "e = 1.6*10**-19 #in C\n", "n_d = 1/(Rho*e*Miu_d) #in /cm^3... correction\n", "\n", "#RESULTS\n", "print('The number of donor is =%.2f X 10^15 atom per cm^3' %(n_d/(10**15)))\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The number of donor is =1.25 X 10^15 atom per cm^3\n" ] } ], "prompt_number": 38 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example No 2.12 Page No 90" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "d = 5.32 #in gm/cc\n", "N_A = 6.02*10**23 #in atoms/gm.mole\n", "At = 72.6 #atomic weight\n", "Miu = 3800 #in cm^2/v.s\n", "\n", "#CALCULATIONS\n", "n_d = (N_A/At) * d #in /cm^3\n", "n_d = n_d * 10**-8 #in /cc\n", "e = 1.6*10**-19 #in C\n", "Sigma = n_d * Miu * e #in mho/cm\n", "\n", "#RESULTS\n", "print('The conductivity of specimen is =%.2f mho/cm' %Sigma)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The conductivity of specimen is =0.27 mho/cm\n" ] } ], "prompt_number": 39 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example No 2.13 Page No 90" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "Rho = 0.3623*10**-3 #in ohm m\n", "d = 4.42*10**28 #Ge density in atoms/m^3\n", "\n", "#CALCULATIONS\n", "Sigma = 1/Rho #in mho/m\n", "n_d = d*10**-6 #in atoms/m^3\n", "e = 1.6*10**-19 #in C\n", "Miu = Sigma/(n_d*e) #in m^2/V.sec\n", "\n", "#RESULTS\n", "print('The electron mobility is =%.2f m^2/V-sec' %Miu)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The electron mobility is =0.39 m^2/V-sec\n" ] } ], "prompt_number": 40 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example No 2.14 Page No 91" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "N_A = 6.025*10**26 #in /kg.Mole\n", "At = 72.59 #atomic weight\n", "d = 5.36*10**3 #in kg/m^3\n", "R = 0.42 #in ohm m\n", "B_i = 10**-6 #rate of boron impurity in %\n", "e = 1.6*10**-19 #in C\n", "\n", "#CALCULATIONS\n", "n = (N_A/At)*d #number of Ge atoms\n", "h = n/10**8 #holes per unit volume\n", "Miu_h = 1/(R*h*e) #in m^2/V.sec\n", "\n", "#RESULTS\n", "print('The Mobility of holes is =%.2f m^2/V-sec' %Miu_h)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Mobility of holes is =0.03 m^2/V-sec\n" ] } ], "prompt_number": 41 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.15 Page No 90" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "n_i = 2*10**19 #in /m^3\n", "Miu_e = 0.36 #in m^2/v.s\n", "Miu_h = 0.17 #in m^2/v.s\n", "\n", "#CALCULATIONS\n", "A = 1*10**-4 #in m^2\n", "V = 2 #in Volts\n", "l = 0.3 #in mm\n", "l = l * 10**-3 #in m\n", "e = 1.6*10**-19 #in C\n", "Sigma_i = n_i * e * (Miu_e+Miu_h) #in mho/m\n", "I = (Sigma_i * V*A)/l #in amp \n", "\n", "#RESULTS\n", "print('The current in amp is =%.2f ' %I)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The current in amp is =1.13 \n" ] } ], "prompt_number": 42 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.16 Page No 92" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "d = 4.2*10**28 #in atoms/m^3\n", "n_d = d/10**6 #in atoms/m^3\n", "e = 1.6*10**-19 #in C\n", "Miu_e = 0.36 #in m^2/V-sec\n", "\n", "#CALCULATIONS\n", "Sigma_n = n_d *e *Miu_e #in mho/m\n", "Rho_n = 1/Sigma_n #ohm m\n", "\n", "#RESULTS\n", "print('The resistivity in \u03a9m is =%.2f X 10^-3' %(Rho_n*(10**3)))\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The resistivity in \u03a9m is =0.41 X 10^-3\n" ] } ], "prompt_number": 43 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.17 Page No 92" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "n_i = 1*10**19 #in /m^3\n", "Miu_e = 0.36 #in m^2/volt.sec\n", "Miu_h = 0.17 #in m^2/volt.sec\n", "A = 2 #in cm^2\n", "A = A * 10**-4 #in m^2\n", "t = 0.1 #in mm\n", "t = t*10**-3 #in m\n", "V = 4 #in volts\n", "e = 1.6*10**-19 #in C\n", "\n", "#CALCULATIONS\n", "Sigma_i = n_i * e * (Miu_e + Miu_h) #mho/m\n", "J = Sigma_i * (V/t) #in Amp/m^2\n", "I = J*A #in Amp\n", "\n", "#RESULTS\n", "print('The current in Amp is =%.2f ' %I)\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The current in Amp is =6.78 \n" ] } ], "prompt_number": 44 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example No 2.18 Page No 92" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "Miu_h = 500.0 #in cm^2/V.s\n", "Miu_e = 1500.0 #in cm^2/V.s\n", "n_i = 1.6*10**10 #in /cm^3\n", "e = 1.6*10**-19 #in C\n", "\n", "#CALCULATIONS\n", "Sigma_i = n_i * e * (Miu_e+Miu_h) #in mho/cm\n", "\n", "#RESULTS\n", "print('The conductivity of pure silicon in mho/cm is =%.2f X 10^-6 ' %(Sigma_i*(10**6)))\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The conductivity of pure silicon in mho/cm is =5.12 X 10^-6 \n" ] } ], "prompt_number": 45 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.19 Page No 96" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "Si_density = 10.5 #in gm/cc\n", "N_A = 6.025*10**23 \n", "At = 108.0 #atomic weight\n", "B = 0.8 #in Tesla\n", "w = 0.50 #in cm\n", "w = w * 10**-2 #in m\n", "t = 0.10 #in mm\n", "t = t * 10**-3 #in m\n", "A = w*t #in m^2\n", "q = 1.6*10**-19 #in C\n", "I = 2 #in ampere\n", "\n", "#CALCULATIONS\n", "n = (N_A/At) * Si_density #in /cc\n", "n = n * 10**6 #in /m^3\n", "V_H = (B*I*t)/(n*q*A) #in volts\n", "\n", "#RESULTS\n", "print('The hall voltage produced is =%.3f X 10^-7 volts' %(V_H*(10**7)))\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The hall voltage produced is =0.341 X 10^-7 volts\n" ] } ], "prompt_number": 46 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.20 Page No 96" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "Sigma = 5.8*10**7 #in mho/m\n", "l = 1 #in m\n", "d = 1 #in cm\n", "d = d * 10**-2 #in m\n", "W = 1 #in mm \n", "W = W*10**-3 #in m\n", "I = 1 #in Amp\n", "B = 1 #in Tesla\n", "V_H = 0.074*10**-6 #in Volts\n", "A = 10**-2 * 10**-3 #in m^2\n", "\n", "#CALCULATIONS\n", "R_H = (V_H*A)/(B*I*d) #in m^3/c\n", "Miu = Sigma * R_H #in m^2/volt.sec\n", "\n", "#RESULTS\n", "print('Hall coefficient is =%.1f X 10^-11 m^3/c' %(R_H*(10**11)))\n", "print('The mobility of electron is = %.2f X 10^-3 m^2/volt.sec ' %(Miu*(10**3)))\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Hall coefficient is =7.4 X 10^-11 m^3/c\n", "The mobility of electron is = 4.29 X 10^-3 m^2/volt.sec \n" ] } ], "prompt_number": 47 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.21 Page No 97" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "n_i = 1.4*10**18 #in /m^3\n", "n_D = 1.4*10**24 #in /m^3\n", "n = n_D #in /m^3\n", "\n", "#CALCULATIONS\n", "p = n_i**2/n #in /m^3\n", "R_e = n/p #Ratio of electron\n", "\n", "#RESULTS\n", "print('Concentration of is =%.2f X 10^12 holes per m^3 ' %(p/(10**12)))\n", "print('Ratio of electron to hole concentration is =%.f 10^12 ' %(R_e/(10**12)))" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Concentration of is =1.40 X 10^12 holes per m^3 \n", "Ratio of electron to hole concentration is =1 10^12 \n" ] } ], "prompt_number": 48 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.22 Page No 97" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "B = 0.48 #in Wb/m^2\n", "R_H = 3.6 * 10**-4 #in m^3/c\n", "R = 9*10**-3 #in ohm-m\n", "\n", "#CALCULATIONS\n", "Sigma = 1/R #in (ohm-m)^-1\n", "Rho = 1/R_H #in coulomb/m^3\n", "e = 1.6*10**-19 #in C\n", "n = Rho/e #in /m^3\n", "Miu = Sigma * R_H #in m^2/volt-s\n", "\n", "#RESULTS\n", "print('The mobility of electron is =%.2f m^2/volt-s' %Miu)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The mobility of electron is =0.04 m^2/volt-s\n" ] } ], "prompt_number": 49 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.23 Page No 104" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#initialisation of variables\n", "e = 1.6*10**-19 #in C\n", "R_H = 0.0145 #in m^3/coulomb\n", "Miu_e = 0.36 #m^2/v-s\n", "E = 100 #V/m\n", "\n", "#CALCULATIONS\n", "n = 1/(e*R_H) #in /m^3\n", "J= n*e*Miu_e*E #in A/m^2\n", "\n", "#RESULTS\n", "print('The current density is =%.2f A/m^2 ' %J)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The current density is =2482.76 A/m^2 \n" ] } ], "prompt_number": 50 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.24 Page No 105" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#initialisation of variables\n", "e = 1.6*10**-19 #in C\n", "Miu_e = 7.04*10**-3 #in m^2/volt-sec\n", "n = 5.8*10**28 #number of electron/m^3\n", "m = 9.1*10**-31\n", "E_F = 5.5 # in eV\n", "\n", "#CALCULATIONS\n", "Torque = (Miu_e/e)*m # in sec \n", "Rho = 1/(n*e*Miu_e) #in ohm cm\n", "V_F = math.sqrt( (2*E_F*e)/m ) #in m/s\n", "\n", "#RESULTS\n", "print('Relaxtion time is =%.2f X 10^-15 sec ' %(Torque*(10**15)))\n", "print('Resistivity of conductor is =%.2f X 10^-18 in \u03a9m' %(Rho*(10**8)))\n", "print('Velocity of electron with the fermi energy is =%.2f X 10^-6 in m/s' %(V_F/(10**6)))\n", "\n", "# Note: The calculation of Part (ii) is wrong also the unit of resistivity of conductor is wrong\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Relaxtion time is =40.04 X 10^-15 sec \n", "Resistivity of conductor is =1.53 X 10^-18 in \u03a9m\n", "Velocity of electron with the fermi energy is =1.39 X 10^-6 in m/s\n" ] } ], "prompt_number": 51 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.25 Page No 105" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#initialisation of variables\n", "\n", "E= 5.95 #in eV\n", "EF= 6.25 #in eV\n", "delE= 0.01\n", "\n", "#CALCULATIONS\n", " #delE= 1-1/(1+exp((E-EF)/KT))\n", "K=1.38*10**-23 #Boltzman Constant in J/K\n", "T = ((E-EF)/math.log(1/(1-delE) -1)*1.6*10**-19)/K #in K\n", "\n", "#RESULTS\n", "print('The temperature is =%.2f K' %T)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The temperature is =756.95 K\n" ] } ], "prompt_number": 52 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.26 Page No 105" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#initialisation of variables\n", "\n", "T1 = 400.0 #in K\n", "T2 = 300.0 #in K\n", "N_V = 1.04*10**19 #in cm^-3\n", "\n", "#CALCULATIONS\n", "N1 = N_V*((T1/T2)**(3/2)) #in cm^-3\n", "KT = 0.0259*(T1/T2) #in eV\n", "FermiLevel= 0.27 #in eV\n", "P_O = N1*math.exp( (-FermiLevel)/KT ) #in cm^-3\n", "\n", "#RESULTS\n", "print('The thermal equillibrium hole concentration is =%.2f X 10^15 cm^-3' %(P_O/(10**15)))\n", "print('Approximationa error ')\n", "# Answer in the book is wrong" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The thermal equillibrium hole concentration is =5.58 X 10^15 cm^-3\n", "Approximationa error \n" ] } ], "prompt_number": 53 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.27 Page No 107" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#initialisation of variables\n", "T1 = 550.0 #in K\n", "T2 = 300.0 #in K\n", "N1 = 1.04*10**19 \n", "\n", "#CALCULATIONS\n", "N_V = N1*((T1/T2)**(3)) \n", "N_C = 2.8*10**19\n", "E_g = -1.12\n", "KT = 0.0259*(T1/T2)\n", "n_i = math.sqrt(N_C*N_V*math.exp(E_g/KT)) #in cm^-3\n", "Nd= math.sqrt(n_i**2/((1.05-1/2.0)**2-(1/2.0)**2))\n", "\n", "\n", "#RESULTS\n", "print('The value of n_i is =%.2f X 10^14 cm^-3' %(n_i/(10**14)))\n", "print('The value of N_d is =%.2f X 10^15 cm^-3' %(Nd/(10**15)))\n", "#Formula n_o= Nd/2+sqrt((Nd/2)^2+n_i^2) and n_o = 1.05*N_d;\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The value of n_i is =3.20 X 10^14 cm^-3\n", "The value of N_d is =1.40 X 10^15 cm^-3\n" ] } ], "prompt_number": 54 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ " Example No 2.28 Page No 106" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#initialisation of variables\n", "n_o = 10**15 #in cm^-3\n", "n_i = 10**10 #in cm^-3\n", "p_o = 10**5 #in cm^-3\n", "del_p = 10**13 #in cm^-3\n", "\n", "#CALCULATIONS\n", "del_n = del_p #in cm^-3\n", "KT= 0.0259 #in eV\n", "Fermi_level1= KT*math.log(n_o/n_i) #in eV\n", "Fermi_level2= KT*math.log((n_o+del_n)/n_i) #in eV\n", "Fermi_level3= KT*math.log((p_o+del_p)/n_i) #in eV\n", "\n", "\n", "#RESULTS\n", "print('Fermi level for thermal equillibrium is : =%.2f eV ' %Fermi_level1)\n", "print('Quasi-Fermi level for electrons in non equillibrium is : =%.2f eV' %Fermi_level2)\n", "print('Quasi-Fermi level for holes in non equillibrium is: =%.2f eV' %Fermi_level3)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Fermi level for thermal equillibrium is : =0.30 eV \n", "Quasi-Fermi level for electrons in non equillibrium is : =0.30 eV\n", "Quasi-Fermi level for holes in non equillibrium is: =0.18 eV\n" ] } ], "prompt_number": 55 } ], "metadata": {} } ] }