Properties of Ge, Si, and GaAs at 300 oK

Property
Ge
Si
GaAs
SiO2
Atoms or Molecules/cm3 4.42 x 1022 5.0 x 1022 4.42 x 1022 2.3 x 1022
Atomic of Molecular weight 72.6 28.08 144.63 60.08
Density, g/cm3 5.32 2.33 5.32 2.27
Breakdown field, V/cm> ~10 5 ~3X10 5 ~4X10 5 ~10 7
Crystal structure Diamond Diamond Zinc blend Amorphous
Density, g/cm3 5.32 2.33 5.32 2.27
Dielectric constant 16 11.8 13.3 3.9
Effective density of states:
    Valence band Nv, cm-3
6.1 x 1019 1.04 x 1019 7.0 x 1018  
Effective density of states:
    Conduction band Nc, cm-3
1.04 x 1019 2.8 x 1019 4.7 x 1017  
Electron afinity X, V 4.0 4.05 4.07 0.9
Energy gap, eV 0.68 1.12 1.43 9
Intrinsic carrier concentration, ni, cm3 2.4 x 1013 1.5 x 1010 1.8 x 106  
Lattice constant, nm 0.5646 0.5431 0.5653  
Effective mass:
    Electrons
me = 0.22m
m*e = 0.12m
me = 0.33m
m*e = 0.26m
0.063m  
Effective mass:
    Holes
mh = 0.31m
m*h = 0.23m
mh = 0.5m
m*h = 0.16m
0.05m  
Intrinsic mobility:
    Electron, cm2/V-s
3900 1500 8600  
Intrinsic mobility:
    Hole, cm2/V-s
1900 450 400  
Temperature coefficient of expansion, oC-1 5.8 x 10-6 2.6 x 10-6 6.8 x 10-6 5 x 10-6
Thermal conductivity, W/cm -oC 0.6 1.5 0.46 0.01

Physical Constants

Constant
Symbol
Magnitude
Avagadro's Number
NA
6.023 x 1023 molecules/mole
Boltzmann's constant
k
1.38 x 10-23 J/K = 8.62 x 10-5 eV/K
Electronic charge
q
1.6 x 10-19 C
Electronvolt
eV
1.6 x 10-19 J
Planks constant
h
6.625 x 10-34 J-s
Thermal voltage at 300 oK
Vt
25.8 mV
Velocity of light
c
3 x 1010 cm/s
Permeability of free space
uo
1.257 x 10-8 H/cm
Permittivity of free space
eo
8.854 x 10-14 F/cm
Free-electron mass
m
9.1 x 10-31 kg

Carrier Mobility in Silicon

Doping
cm-3
Electron
Mobility
(cm2 V-sec)
Hole
Mobility
(cm2 V-sec)
1014
1500
450
1015
1500
450
1016
1400
440
1017
1200
410
1018
800
200
1019
200
150
1020
90
50
Actual mobility values will vary.