1 / 21

ECE 874: Physical Electronics

ECE 874: Physical Electronics. Prof. Virginia Ayres Electrical & Computer Engineering Michigan State University ayresv@msu.edu. Lecture 26, 27 Nov 12 Chp. 05: Recombination-Generation Processes. baseline situation. W. Reverse biassed pn junction:. Ideally in depletion region W: p = n = 0

sulwyn
Télécharger la présentation

ECE 874: Physical Electronics

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ECE 874:Physical Electronics Prof. Virginia Ayres Electrical & Computer Engineering Michigan State University ayresv@msu.edu

  2. Lecture 26, 27 Nov 12Chp. 05: Recombination-Generation Processes VM Ayres, ECE874, F12

  3. baseline situation W VM Ayres, ECE874, F12

  4. Reverse biassed pn junction: • Ideally in depletion region W: p = n = 0 • (always do have thermally generated ni/pi but internal field E in W continuously sweeps them out) VM Ayres, ECE874, F12

  5. New stuff in the picture: the effect of light VM Ayres, ECE874, F12

  6. Effect of shining light on reverse biassed pn junction: • In depletion region W: p = n ≠ 0 • In depletion region W: p = n = large • In depletion region W: VM Ayres, ECE874, F12

  7. xpp VM Ayres, ECE874, F12

  8. VM Ayres, ECE874, F12

  9. VM Ayres, ECE874, F12

  10. VM Ayres, ECE874, F12

  11. Lecture 26, 27 Nov 12Chp. 06: Currents VM Ayres, ECE874, F12

  12. General assuming capture/emission coefficients don’t change much from equilibrium values: Steady state: (5.24) Equilibrium: 0 VM Ayres, ECE874, F12

  13. Now include the ordinary mechanisms that can change n and p:drift currents and diffusion currents And anything else! drift diffusion VM Ayres, ECE874, F12

  14. Now include the ordinary mechanisms that can change n and p:drift currents and diffusion currents And anything else! VM Ayres, ECE874, F12

  15. Now include the ordinary mechanisms that can change n and p:drift currents and diffusion currents And anything else! 6.1: review of drift 6.2: review of diffusion 6.3: list of equations for dn/dt, dp/dt and J’s – no new material VM Ayres, ECE874, F12

  16. Hw06 Prs. 6.3 and 6.4: Diffusion: diff diff A diffusion current happens anytime you have a spatial variation in the concentrations of n or p VM Ayres, ECE874, F12

  17. Example problem: from Pr. 6.4: Put a red box around any region where n-type ness changes: dn/dx Put a blue box around any region where p-type ness changes: dp/dx -L -L/2 0 L/2 L VM Ayres, ECE874, F12

  18. Example problem: from Pr. 6.4: Put a red box around any region where n-type ness changes: dn/dx Put a blue box around any region where p-type ness changes: dp/dx -L -L/2 0 L/2 L VM Ayres, ECE874, F12

  19. Example problem: from Pr. 6.4: hole VM Ayres, ECE874, F12 -L -L/2 0 L/2 L

  20. VM Ayres, ECE874, F12

  21. VM Ayres, ECE874, F12

More Related