hw6_solutions

hw6_solutions - ECE 440 Homework VI Due: Wednesday, October...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
ECE 440 Homework VI Fall 2008 Due: Wednesday, October 08, 2008 1. Consider a silicon sample at 300 K. Assume that the electron concentration varies linearly with distance. At x=0, the electron concentration is n(0). At x=10 μm, the electron concentration is n(10μm)= 5x10 14 /cm 3 . If the electron diffusion coefficient, assumed constant, is D n =30 cm 2 /sec, determine the electron concentration at x=0 for the following two diffusion current densities: (a) the diffusion current density is found to be J n diff = + 0.9 A/ cm 2 and (b) J n diff = - 0.9 A/cm 2 . 2. The acceptor profile of a silicon sample is shown below. Assume that the majority carrier mobility can be obtained from Fig. 3-23 (or the enlarged graph posted in the 440 website), and the sample is at thermal equilibrium at 300 K. (a) Determine the diffusion coefficients for majority carriers at points A, B and C, respectively. To find the diffusion coefficients, we have to first find the doping concentrations at those
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 6

hw6_solutions - ECE 440 Homework VI Due: Wednesday, October...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online