material and device ( electrical engineering )
- Draw the band diagram for p-type silicon with a hole concentration of 1014cm-3. Look up the constants for silicon at room temperature in your books, or online.
- If the electron concentration in silicon is 1018cm-3, what is the hole concentration?
- If the Fermi level is in the middle of the bandgap, what is the electron and hole concentration for Silicon at room temperature?
- If the Fermi level, Ef is 0.3 eV above Ei, what is the electron concentration? What is the hole concentration?
- Write down an exponential equation for the electron concentration in silicon as a function of Ef position.
- If the mobility of electrons in my silicon is 1000cm2/Vs, and the electric field across it is 103V/cm, what is the drift velocity of the electrons?
- Using the electron velocity above, what is the resistivity of Silicon, assuming the electron concentration is 1016cm-3? Compare this with the resistivity of glass, and copper.
- Explain what drift and diffusion are. How are they related?
- Explain using a few paragraphs, and some pictures, how a pn diode works. Make sure to include a band diagram, and also explain why current flows only in one direction and not the other.