Semiconductor physics

What is the process called in which electrons and holes recombine through deep levels (traps) in the band gap?

  1. ASRH (Shockley-Read-Hall) recombination
  2. BRadiative recombination
  3. CAuger recombination
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Answer: A. SRH (Shockley-Read-Hall) recombination

Recombination of electrons and holes in steps through deep levels created by metal impurities or crystal defects is called SRH recombination. In indirect-gap semiconductors such as silicon, it is the dominant recombination process and a major factor determining minority carrier lifetime.

  • A. Correct. Recombination through traps is SRH recombination.
  • B. Radiative recombination is the direct recombination of an electron and a hole with light emission, common in direct-gap semiconductors.
  • C. Auger recombination passes the released energy to another carrier and becomes significant at high carrier densities.
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More Semiconductor physics questions

  1. With minority carrier diffusion coefficient D and lifetime τ, which expression gives the diffusion length L?
  2. How does the band gap of silicon change as the temperature rises?
  3. What happens to the drift velocity of electrons in silicon when a strong electric field is applied?
  4. Which value is closest to the energy of a single photon of light with a wavelength of 620 nm? (E [eV] ≈ 1240 / λ [nm])
  5. How does carrier mobility generally change when the impurity concentration in silicon is increased?