514 APPENDIX A. ALIST OF SYMBOLS
p momentum of a particle
p hole concentration in the valence band
pi intrinsic hole concentration in the valence band
pa holes bound to acceptors
pcv momentum matrix element for an optical transition between the
valence and conduction band
pn(pp) equilibrium hole density in then-side (p-side) of ap-njunction
Pop optical power density (energy flow/sec/area)
Qs total charge (per area) in an MOS channel
Qn total mobile charge (per area) in an MOS channel
Qss surface charge density in an MOS capacitor
Qdep depletion charge (per area) in an MOS channel
Rspon total rate at which an electron-hole system recombines to emit
photons by spontaneous recombination
Rs,RG,RDparasitic resistances associated with the source, gate and
drain of a transistor respectively
RL load resistance
R∗ Richardson constant in a Schottky barrier
ttr transit time of a carrier through a channel
T tunneling probability
U(r) position dependent potential energy
v velocity of the electron
vs saturation velocity of the carrier (electron, hole)
Vbi built-in voltage
VG gate bias (referred to the source)
VD drain bias
Vp pinch-off voltage to deplete the channel of an FET
VT threshold gate bias for pinch-off
Vfb flat band voltage. Voltage needed to make the semiconductor bands
flat in an MOS capacitor