{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

01_exam1fall - Page 1 of 8 YOUR NAME Department of...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Page 1 of 8 YOUR NAME________________________________ Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology 6.012 Electronic Devices and Circuits Exam No. 1 Notes: 1. Unless otherwise indicated, assume room temperature and that kT/q is 0.025 V. You may also approximate [(kT/q) ln 10] as 0.06 V. 2. Open book: 6.012 text and one sheet of notes permitted. 3. All of your answers and any relevant work must appear on these pages. Any additional paper you hand in will not be graded. 4. Make reasonable approximations and assumptions. State and justify any such assumptions and approximations you do make. 5. Be careful to include the correct units with your answers when appropriate. 6. Be certain that you have all eight (8) pages of this exam booklet and make certain that you write your name at the top of this page in the space provided. 6.012 Staff Use Only PROBLEM 1 (out of a possible 33) PROBLEM 2 (out of a possible 33) PROBLEM 3 (out of a possible 34) TOTAL
Image of page 1

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

View Full Document Right Arrow Icon
Your name Page 2 of 8 Problem 1 - (33 points) This question concerns several silicon samples. In these samples the electron mobility, µ e , is 1600 cm 2 /V-s; the hole mobility, µ h , is 600 cm 2 /V-s; the minority carrier -3 lifetime, t min , is 10 -5 s; and the intrinsic carrier concentration, n i , is 10 10 cm at room temperature. Except in Part e, there are no contacts on these samples and all of their surfaces are reflecting boundaries, i.e. there is no extra recombination there. a) One sample is doped with 1 x 10 16 cm -3 boron atoms and 2 x 10 16 cm -3 phosphorous atoms. Indicate whether this sample is n-type or p-type, and determine the thermal equilibrium hole and electron concentrations, p o and n o , respectively, in it and its electrostatic potential, f , realtive to intrinsic silicon. Show your work and/or o explain your answer. Type: ___________ _______ -3 p o = __________________ cm -3 n = __________________ cm o f = _________________ Volts o b) What are the diffusion lengths of holes and electrons, L h and L e , respectively, in the sample of Part a? Show your work and/or explain your answer.
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern