(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Assume silicon, at room temperature (300k) and complete ionization.

An abrupt n+-p junction with Nd=10^20 cm^-3 and Na=10^17 cm^-3 is forward biased at 0.5V

2. Relevant equations

a)Draw the band diagram, label n and p regions, show direction of the current flow. Also what is the current type (electrons or holes, drift or diffusion) in the p-type region just outside the depletion region?

b)Calculate the depletion charge capacitance per unit area.

3. The attempt at a solution

I have managed to draw the band diagram but I'd appreciate it if there was a way I could check my answers. Also I get confused with the wording for the 2nd portion of part A. I understand that the current in a forward biased pn junction is due to diffusion would this be considered the same for p-type region?

For part B would it be correct if I use the equation

C'=[(eεsNaNd)/(2(Vbi-Vr)(Na+Nd))]^1/2

But I get stuck since C=AC' but I can't seem to figure out the value for A, would I be able to use A=10^-4cm^2?

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: Forward biased PN junction help needed

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

**Physics Forums | Science Articles, Homework Help, Discussion**