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*Applet Tutorial*

- Depletion thickness
- The depletion thicknesses, xp and xn, represent the distance of the depeletion edge from the junction.
- Change the doping level of one side at steps of a factor ten. Record on paper both depletion thicknesses at each doping level.
- Based on your data, what is the mathematical relationship of xp and xn to Na and Nd ? Write down a single equation that involves all these four parameters. Check your answer.
- What does this relation mean physically about the total space charge ? Check your answer.
- Band diagram
- Hide the applet page by scrolling down the text or minimizing your web browser.
- Draw on paper the band diagram of PN junction for Na = 1E16 and Nd = 1E15. Make the band diagram correct both quantitatively (in the relative depletion thickness of the two sides) and qualitatively (shape of band diagram).
- Use the applet to check if your diagram is correct.
- Can you draw the band diagram for a PNP structure where Na = 1E18, Nd = 1E17, and Na = 1E15 ? Assume that the N-layer thickness is greater than the sum of the depletion thicknesses from the two junctions.

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