Note: Potential Barrier (Cut in voltage or Knee voltage Vγ ) is developed across
a depletion layer which is approximately 0.5
to 0.7v for silicon diodes (diode conductivity is temperature dependant) and
approximately 0.3 of a volt for
germanium diodes. When a junction diode is Forward Biased the
thickness of the depletion region reduces and the diode acts like a short
circuit allowing full current to flow. When a junction diode is Reverse
Biased the thickness of the depletion region increases and the diode acts
like an open circuit blocking any current flow, (only a very small leakage
current).Hence Potential Barrier is 0.7v
for silicon diodes ( at 25° centigrade).
FORMULA :
Forward bias Static resistance (Rs) =VF/IF (ohms)
Forward bias Dynamic resistance (Rd)
=∆VF/∆IF (ohms)
