A | area; cross sectional area; amplification |
a | lattice parameter; acceleration; amplitude of vibrations; half-channel thickness in a JFET (Ch. 6) |
a (subscript) | acceptor, e.g. N_{a} = acceptor concentration (m^{-3}) |
ac | alternating current |
a_{o} | Bohr radius (0.0529 nm) |
A_{V}, A_{P} | voltage amplification, power amplification |
APF | atomic packing factor |
B, B | magnetic field vector (T), magnetic field |
B | frequency bandwidth |
B_{c} | critical magnetic field |
B_{m} | maximum magnetic field |
B_{o}, B_{e} | Richardson-Dushman constant, effective Richardson-Dushman constant |
BC | base collector |
BCC | body-centered cubic |
BE | base emitter |
BJT | bipolar junction transistor |
C | capacitance; composition; the Nordheim coefficient (W m) |
c | speed of light (3x10^{8} m s^{-1}); specific heat capacity (J K^{-1} kg^{-1}) |
C_{dep} | depletion layer capacitance |
C_{m} | molar heat capacity (J K^{-1} mol^{-1}) |
C_{diff} | diffusion (storage) capacitance of a forward-biased pn junction |
CB | conduction band; common base |
CE | common emitter |
CMOS | complementary MOS |
CN | coordination number |
CVD | chemical vapor deposition |
D | diffusion coefficient (m^{2} s^{-1}); thickness; electric displacement (C m^{-2}) |
d | density (kg m^{-3}); distance; separation of the atomic planes in a crystal, separation of capacitor plates; piezoelectric coefficient |
d(subscript) | donor, e.g., N_{d} = donor concentration (m^{-3}) |
dc | direct current |
d_{ij} | piezoelectric coefficients |
E | energy; electric field (V m^{-1}) (Ch. 9) |
E_{a}, E_{d} | acceptor and donor energy levels |
E_{c}, E_{v} | conduction band edge, valence band edge |
E_{ex} | exchange interaction energy |
E_{F}, E_{FO} | Fermi energy, Fermi energy at 0 K |
E_{g} | bandgap energy |
E_{mag} | magnetic energy |
E | electric field (V m^{-1}) |
E_{br} | dielectric strength or breakdown field (V m^{-1}) |
E_{loc} | local electric field |
e | electronic charge (1.60218x10^{-19} C) |
e (subscript) | electron, e.g., m_{e} = electron drift mobility |
eff (subscript) | effective, e.g., m_{eff} = effective drift mobility |
EHP | electron-hole pair |
EM | electromagnetic |
EMF (emf) | electromagnetic force (V) |
F | force (N); function |
f | frequency; function |
f(E) | Fermi-Dirac function |
FCC | face-centered cubic |
FET | field effect transistor |
G | rate of generation |
G_{ph} | rate of photogeneration |
G_{p} | parallel conductance (W^{-1}) |
g(E) | density of states |
g | conductance; transconductance (A/V) |
g_{d} | incremental or dynamic conductance (A/V) |
g_{m} | mutual transconductance (A/V) |
H, H | magnetic field intensity (strength), or magnetizing field (A m^{-1}) |
h | Planck's constant (6.6261x10^{-34} J s) |
h | Planck's constant divided by 2p (1.0546x10^{-34} J s) |
h (subscript) | hole, e.g., m_{h} = hole drift mobility |
h_{FE}, h_{fe} | dc current gain, small signal (ac) current gain in the common emitter configuration |
HCP | hexagonal close-packed |
HF | high frequency |
I | electric current (A); moment of inertia (kg m^{2}) (Ch.1) |
I | light intensity (W m^{-2}) |
I_{br} | breakdown current |
I_{B}, I_{C}, I_{E} | base, collector and emitter currents in a BJT |
i | instantaneous current (A); small signal (ac) current, i = dI |
i (subscript) | intrinsic, e.g., n_{i} = intrinsic concentration |
i_{b}, i_{c}, i_{e} | small signal base, collector and emitter currents (dI_{B}, dI_{C}, dI_{E}) in a BJT |
IC | integrated circuit |
J | current density (A m^{-2}) |
J | total angular momentum vector |
j | imaginary constant |
J_{c} | critical current density (A m^{-2}) |
JFET | junction FET |
K | spring constant (Ch. 1); phonon wavevector (m^{-1}); dielectric constant (Ch. 7) |
k | Boltzmann constant (k = R/N_{A} = 1.3807x10^{-23} J K^{-1}); wavenumber (k = 2p /l), wavevector (m^{-1}); electromechanical coupling factor (Ch. 7) |
KE | kinetic energy |
L | total orbital angular momentum |
L | length; inductance |
l | length; mean free path; orbital angular momentum quantum number |
L_{ch} | channel length in an FET |
L_{e}, L_{h} | electron and hole diffusion lengths |
l_{n}, l_{p} | lengths of the n- and p-regions outside depletion region in a pn junction |
ln (x) | natural logarithm of x |
LCAO | linear combination of atomic orbitals |
M, M | magnetization vector (A m^{-1}), magnetization (A m^{-1}) |
M | multiplication in avalanche effect |
M_{at} | relative atomic mass; atomic mass; "atomic weight" (g mol^{-1}) |
M_{r} | remanent or residual magnetization (A m^{-1}) |
M_{sat} | saturation magnetization (A m^{-1}) |
m | mass (kg) |
m_{e} | mass of the electron in free space (9.10939 x10^{-31} kg) |
m_{e}* | effective mass of the electron in a crystal |
m_{h}* | effective mass of a hole in a crystal |
m_{l} | magnetic quantum number |
m_{s} | spin magnetic quantum number |
MOS (MOST) | metal-oxide-semiconductor (transistor) |
MOSFET | metal-oxide-semiconductor FET |
N | number of atoms or molecules; number of atoms per unit volume (m^{-3}) (Chs. 7 and 9); number of turns of a coil (Ch. 8) |
N_{A} | Avogadro's number (6.022x10^{23} mol^{-1}) |
n | electron concentration (number per unit volume); atomic concentration; principal quantum number; integer number; refractive index (Ch. 9) |
n^{+} | heavily doped n-region |
n_{at} | number of atoms per unit volume |
N_{c}, N_{v} | effective density of states at the conduction and valence band edges (m^{-3}) |
N_{d}, N_{d}^{+} | donor and ionized donor concentrations (m^{-3}) |
n_{e}, n_{o} | refractive index for extraordinary and ordinary waves in a birefringent crystal |
n_{i} | intrinsic concentration (m^{-3}) |
n_{no}, p_{po} | equilibrium majority carrier concentrations (m^{-3}) |
n_{po}, p_{no} | equilibrium minority carrier concentrations (m^{-3}) |
N_{S} | concentration of electron scattering centers |
n_{v} | velocity density function; vacancy concentration (m^{-3}) |
P | probability; pressure (Pa); power (W) or power loss (W) |
p, P | electric dipole moment (C m) |
p | hole concentration (m^{-3}); momentum (kg m s^{-1}); pyroelectric coefficient (Ch. 7) |
p^{+} | heavily doped p-type |
p_{av} | average dipole moment per molecule |
p_{e} | electron momentum (kg m s^{-1}) |
PE | potential energy |
p_{induced} | induced dipole moment (C m) |
p_{o} | permanent dipole moment (C m) |
PET | polyester, polyethylene terephtalate |
PZT | lead zirconate titanate |
Q | charge (C); heat (J); quality factor |
Q' | rate of heat flow (W) |
q | charge (C) |
R | gas constant (N_{A}k = 8.31457 J mol^{-1} K^{-1}); resistance; radius; reflection coefficient (Ch. 3); rate of recombination (Ch. 5) |
R | reflectance (Ch. 9) |
r | position vector |
r | radial distance; radius; interatomic separation; resistance per unit length |
r | reflection coefficent (Ch. 9) |
R_{H} | Hall coefficient (m^{3} C^{-1}) |
r_{o} | bond length, equilibrium separation |
rms | root mean square |
S | total spin momentum, intrinsic angular momentum; Poynting vector (Ch. 9) |
S | cross-sectional area of a scattering center; Seebeck coefficient, thermoelectric power ( V m^{-1}); strain (Ch.7) |
S_{band} | number of states per unit volume in the band |
S_{j} | strain along direction j |
SCL | space charge layer |
T | temperature in Kelvin; transmission coefficient |
T | transmittance |
t | time (s); thickness (m) |
t | transmission coefficient |
tand | loss tangent |
T_{C} | Curie tempearture |
T_{c} | critical temperature (K) |
T_{j} | mechanical stress along direction j (Pa) |
TC | thermocouple |
TCC | temperature coefficient of capacitance (K^{-1}) |
TCR | temperature coefficient of resistivity (K^{-1}) |
U | total internal energy |
u | mean speed (of electron) (m s^{-1}) |
V | voltage; volume; PE function of the electron, PE(x) |
V_{br} | breakdown voltage |
V_{o} | built-in voltage |
V_{P} | pnich-off voltage |
V_{r} | reverse bias voltage |
u, v | velocity (m s^{-1}); instantaneous voltage (V) |
mean square velocity; mean square voltage | |
u_{dx} | drift velocity in the x direction |
u_{e}, u_{rms} | effective velocity or rms velocity of the electron |
u_{F} | Fermi speed |
u_{g}, v_{g} | group velocity |
u_{th} | thermal velocity |
VB | valence band |
W | width; width of depletion layer with applied voltage; dielectric loss |
W_{o} | width of depletion region with no applied voltage |
W_{n}, W_{p} | width of depletion region on the n-side and on the p-side with no applied voltage |
X | atomic fraction |
Y | admittance (W ^{-1});Young's modulus (Pa) |
Z | impedance (W); atomic number, number of electrons in the atom |
a | polarizability; temperature coefficient of resistivity (K^{-1}); absorption coefficient (m^{-1}); gain or current transfer ratio from emitter to collector of a BJT |
b | current gain I_{C}/I_{B} of a BJT; Bohr magneton (9.2732 x10^{-24} J T^{-1}) |
b_{S} | Schottky coefficient |
g | emitter injection efficiency (Ch. 6); gyromagnetic ratio (Ch. 8) |
G, G_{ph} | flux (m^{-2} s^{-1}), photon flux (photons m^{-2} s^{-1}) |
d | small change; skin depth (Ch. 2); loss angle (Ch.7) |
D | change, excess (e.g., Dn = excess electron concentration) |
^{2} | ^{2}/x^{2} + ^{2}/y^{2} + ^{2}/z^{2} |
e | e_{o}e_{r} , permittivity of a medium (C V^{-1} m^{-1} or F m^{-1}); elastic strain |
e_{o} | permittivity of free space or absolute permittivity (8.8542x10^{-12} C V^{-1} m^{-1} or F m^{-1}) |
e_{r} | relative permittivity or dielectric constant |
h | efficiency; quantum efficiency; ideality factor |
q | angle; an angular spherical coordinate; thermal resistance; angle between a light ray and normal to a surface (Ch. 9) |
k | thermal conductivity (W m^{-1} K^{-1}); dielectric constant |
l | wavelength (m); thermal coefficient of linear expansion (K^{-1}); characteristic length (Ch. 8) |
m | e_{o}e_{r}, magnetic permeability (H m^{-1}); chemical potential (Ch.5) |
m_{o} | absolute permeability (4px10^{-7} H m^{-1}) |
m_{r} | relative permeability |
m_{m} | magnetic dipole moment (A m^{2}) |
m_{d} | drift mobility (m^{2} V^{-1} s^{-1}) |
m_{h} , m_{e} | hole drift mobility, electron drift mobility (m^{2} V^{-1} s^{-1}) |
n | frequency (Hz); Poisson's ratio |
p | pi, 3.14159... |
P | Peltier coefficient (V) |
r | resistivity (W m); density (kg m^{-3}); charge density (C m^{-3}) |
r_{E} | energy density (J m^{-3}) |
r_{net} | net space charge density (C m^{-3}) |
rJ^{2} | Joule heating per unit volume (W m^{-3}) |
s | electrical conductivity (W^{-1} m^{-1}); surface concentration of charge (C m^{-2}) (Ch. 7) |
s_{P} | polarization charge density (C m^{-2}) |
s_{o} | free surface charge density (C m^{-2}) |
s_{S} | Stefan's constant (5.670x10^{-8} W m^{-2} K^{-4}) |
t | time constant; mean electron scattering time; relaxation time; torque (N m) |
t_{g} | mean time to generate an electron-hole pair |
f | angle; an angular spherical coordinate |
F | work function (J or eV); magnetic flux (Wb) |
F_{m} | metal work function (J or eV) |
F_{n} | energy required to remove an electron from an n-type semiconductor (J or eV) |
c | volume fraction; electron affinity; susceptibility (c_{e} is electrical;c_{m} is magnetic) |
Y(x, t) | total wavefunction |
y(x) | spatial dependence of the electron wavefunction under steady state conditions |
y_{k}(x) | Bloch wavefunction, electron wavefunction in a crystal |
y_{hyb} | hybrid orbital |
w | angular frequency (2pu); oscillation frequency (rad s^{-1}) |
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