{
"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",
"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. 62"
]
},
{
"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. 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 2.11 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 2.12 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": {}
}
]
}