Key Points
- A PN diode is a junction between an N-type region
and P-type region
- To establish equilibrium (ie zero flow at zero
applied potential) a space chareg regions (depletion region) must form.
- At Va = 0 Drift cancels diffusion In = 0 Ip=0
- A built in voltage barrier is established
that causes the drift
- Reverse bias increases the potential barrier
- Forward bias decreases the barrier
- Exponential relationship for flow over a barrier
gives J ~ exp(qV/kT)
- Non linear!!!!!
Questions
- What is diode?
- At equilibrium
what happens at the junction of PN interface?
- Draw the bandstructure across a PN junction. Show
the effects of reverse bias and forward bias.
- What causes the non-linearity in a PN junction?
what is the non-linearity?