Semiconductor physics

Which value is closest to the electron mobility in lightly doped silicon at room temperature?

  1. AAbout 14 cm²/(V·s)
  2. BAbout 140,000 cm²/(V·s)
  3. CAbout 1,400 cm²/(V·s)
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Answer: C. About 1,400 cm²/(V·s)

In lightly doped silicon at room temperature, the electron mobility is about 1,400 cm²/(V·s) and the hole mobility about 450 cm²/(V·s). At higher impurity concentrations, these values decrease because of ionized impurity scattering.

  • A. About 14 cm²/(V·s) is two orders of magnitude too small.
  • B. About 140,000 cm²/(V·s) is two orders of magnitude too large; even high-mobility compound semiconductors do not reach this at room temperature.
  • C. Correct. The electron mobility is about 1,400 cm²/(V·s).
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More Semiconductor physics questions

  1. In an indirect-gap semiconductor such as silicon, why is the probability of electron-hole recombination with light emission low?
  2. In a semiconductor driven out of thermal equilibrium by illumination or current injection, what are the levels introduced to describe the electron and hole densities separately?
  3. Which value is closest to the lattice constant of crystalline silicon?
  4. Why is the intrinsic Fermi level of silicon slightly offset from the exact center of the band gap?
  5. Which value is closest to the band gap of silicon (Si) at room temperature?