Unformatted text preview: 2. a) What is the range of bandgap energy you need to have to create a white LED? b) If that range of bandgap energy is not available, how else can you create a white LED? (Hint: The problem requires you to search online.) 3. Explain why Si doped with 10 14 cm-3 Sb is n-type at 400 K but similar doped Ge is not. 4. A Si sample is doped with 8 X 10 16 cm-3 donors and 2 X 10 16 cm-3 acceptors. Find the position of the Fermi level with respect to E i at 300 K. 5. What is the probability that an electron state with energy 0.12 eV above the Fermi energy will be occupied at T= 0K, 200K, and 400K?...
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This note was uploaded on 10/07/2011 for the course EE 2 taught by Professor Vis during the Spring '07 term at UCLA.
- Spring '07