Compound semiconductors

What is the approximate wavelength of light emitted by GaAs, which has a band gap of about 1.42 eV?

  1. AAbout 450 nm (blue)
  2. BAbout 870 nm (near-infrared)
  3. CAbout 10 µm (far-infrared)
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Answer: B. About 870 nm (near-infrared)

The wavelength can be found from the band gap as λ(nm) ≈ 1240 / Eg(eV): 1240 / 1.42 ≈ 873 nm, invisible near-infrared light. GaAs-based LEDs are used, for example, for infrared transmission in remote controls.

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More Compound semiconductors questions

  1. Which correctly describes the typical diameter of wafers for compound semiconductors such as GaAs?
  2. Which is a typical material for high-brightness red to yellow LEDs?
  3. Which correctly describes the quantum well structure used in the light-emitting layers of semiconductor lasers and LEDs?
  4. Which is a characteristic of a VCSEL (vertical-cavity surface-emitting laser)?
  5. Why is care needed when handling GaAs wafer processing debris and waste?