The forward current across the depletion layer of a PN junction
diode consists of electrons
from Ν to Ρ and holes injected from Ρ to N. The ratio of the hole
current crossing
the junction to the total current is known as the injection
efficiency. Determine an
expression for the injection efficiency as a function of:
a) Na/Nd.
b) The ratio of the conductivity of Ρ to that of N.
Assume τp = Ο.1τn , and μp = 2.5
μn...
A2)
i) What is the cause of the junction capacitance and diffusion
capacitance of a pn junction? Under what condition the junction and
diffusion capacitance of the pn junction will exist?
ii) Is the junction capacitance of a pn junction linear? How
about the diffusion capacitance?
Explain the role of forward resistance in PN junction
diode . Differentiate the approximate and simplified diode models
on the basis of forward resistance.
1.pn junction when forward bias is applied
Draw the energy band diagram.
Explain all the quasi fermi levels in the depletion region and why
they are so drawn.
2.pn junction when reverse bias is applied
Draw the energy band diagram.
Explain all the quasi fermi levels in the depletion region and why
they are so drawn.