Unformatted text preview: voltage . At what forward voltage do the bands become flat? Plot the band diagram at V = 1 Volt, and explain the shape of the bands. II) For a long diode, the excess carrier concentration are given by equations (5-31a) and (5-31b) Use the ‘PN Junction Long Base Depletion Approximation’ and plot the peak of excess electron and hole concentration vs. V app . At what voltage do you begin to see high-level injection? III) Theoretical Exercise: a. Explain qualitatively how a forward bias across a pn junction reduces the width of the depletion region. b. For the pn junction considered in this problem, deep in the p-region is the current carried exclusively by electrons or holes? For such case, is the current dominated by drift, diffusion, or both? Justify your answer....
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- Spring '08
- P-n junction, pn junction, pn junction tools