{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 17: BAND THEORY OF SOLIDS" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 17.1: EX17_1.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc \n", "// Given that \n", "a = 3e-10 // side of square lattice in m\n", "h = 6.62e-34 // Planck constant in J sec\n", "e = 1.6e-19 // charge on an electron in C\n", "m = 9.1e-31 // mass of electron in kg\n", "// Sample Problem 1 on page no. 17.18\n", "printf('\n # PROBLEM 1 # \n')\n", "printf('Standard formula used \n ')\n", "printf('E = P^2 / (2*m) \n P = h_cut*k \n')\n", "p = (h / (2 * a))\n", "E = (p^2 / (2 * m)) * (1 / e)\n", "printf('\n Electron momentum value at the sides of first Brilloin zone is %e kg-m/sec.\n Enrgy of free electron is %f eV.',p,E)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 17.2: Calculation_of_Position_of_Fermi_level.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc \n", "// Given that \n", "n = 5e22 // no. of atoms per m^3\n", "t = 300 // room temperature in K\n", "k = 1.37e-23 // Boltzmann's constant in J/K\n", "h = 6.62e-34 // Planck constant in J sec\n", "e = 1.6e-19 // charge on an electron in C\n", "m = 9.1e-31 // mass of electron in kg\n", "// Sample Problem 2 on page no. 17.19\n", "printf('\n # PROBLEM 2 # \n')\n", "printf('Standard formula used \n')\n", "printf('n_c = 2*(2*pi*m*k*T/h^2)^(3/2) * e^(E_f-E_c)/kT \n')\n", "d = (k * t) * log(n * h^3 / (2 * (2 * %pi * m * k * t)^(3/2)))\n", "printf('\n Position of fermi level is %f eV.',-d/e)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 17.3: Calculation_of_New_position_of_Fermi_level.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc \n", "// Given that \n", "E = 0.3 // Fermi energy in eV\n", "T = 330 // temperature in K\n", "t = 300 // room temperature in K\n", "k = 1.37e-23 // Boltzmann's constant in J/K\n", "h = 6.62e-34 // Planck constant in J sec\n", "e = 1.6e-19 // charge on an electron in C\n", "m = 9.1e-31 // mass of electron in kg\n", "// Sample Problem 3 on page no. 17.19\n", "printf('\n # PROBLEM 3 # \n')\n", "printf('Standard formula used \n')\n", "printf('n_c = n_d * e^(E_f-E_c)/kT \n')\n", "d = (T / t) * (E)\n", "printf('\n New position of fermi level is %f eV.',d)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 17.4: Calculation_of_Density_of_holes_and_electron.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc \n", "// Given that \n", "E = 0.7 // band gap for semiconductor in eV\n", "t = 300 // room temperature in K\n", "k = 1.38e-23 // Boltzmann's constant in J/K\n", "h = 6.62e-34 // Planck constant in J sec\n", "e = 1.6e-19 // charge on an electron in C\n", "m = 9.1e-31 // mass of electron in kg\n", "// Sample Problem 4 on page no. 17.20\n", "printf('\n # PROBLEM 4 # \n')\n", "printf('Standard formula used \n')\n", "printf('n_c = 2*(2*pi*m*k*T/h^2)^(3/2) * e^(E_f-E_c)/kT \n')\n", "n = 2 * ((2 * %pi * k * t * m) / h^2)^(3/2) * exp(-(E * e / (2 * k * t)))\n", "printf('\n Density of holes and electron is %e per m^3.',n)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 17.5: Calculation_of_Hall_coefficient.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc \n", "// Given that \n", "n = 5e28 // no. of atoms in per m^3\n", "e = 1.6e-19 // charge on an electron in C\n", "// Sample Problem 5 on page no. 17.20\n", "printf('\n # PROBLEM 5 # \n')\n", "printf('Standard formula used \n')\n", "printf('R_h = 1/(n*e) \n')\n", "R = -(1 / (n * e))\n", "printf('\n Hall coefficient is %e m^3/C.',R)" ] } , { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 17.6: Calculation_of_Hall_coefficient.sce" ] }, { "cell_type": "code", "execution_count": null, "metadata": { "collapsed": true }, "outputs": [], "source": [ "clc \n", "// Given that \n", "a = 4.28e-10 // cell side of Na in m\n", "e = 1.6e-19 // charge on an electron in C\n", "// Sample Problem 6 on page no. 17.20\n", "printf('\n # PROBLEM 6 # \n')\n", "printf('Standard formula used \n')\n", "printf('R_h = 1/(n*e) \n')\n", "n = (2 / a^3)\n", "R = -(1 / (n * e))\n", "printf('\n Hall coefficient is %e m^3/C.',R)" ] } ], "metadata": { "kernelspec": { "display_name": "Scilab", "language": "scilab", "name": "scilab" }, "language_info": { "file_extension": ".sce", "help_links": [ { "text": "MetaKernel Magics", "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md" } ], "mimetype": "text/x-octave", "name": "scilab", "version": "0.7.1" } }, "nbformat": 4, "nbformat_minor": 0 }