Compound semiconductors

Which material is mainly used in the light-emitting layer of deep-ultraviolet LEDs, such as those for sterilization?

  1. AGaAs
  2. BAlGaN (aluminum gallium nitride)
  3. CInP
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Answer: B. AlGaN (aluminum gallium nitride)

The band gap of AlGaN increases as the aluminum fraction increases, so it can emit short deep-ultraviolet wavelengths. Deep-UV LEDs are used to sterilize water and air, but improving their light-emission efficiency remains a challenge. GaAs and InP are used for infrared emission.

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More Compound semiconductors questions

  1. Which is a characteristic of multi-junction solar cells, which stack several compound semiconductor layers with different band gaps?
  2. Which impurity is typically used to make p-type layers in GaN?
  3. What is the typical crystal structure of GaN?
  4. Which is an example of an application of HBTs (heterojunction bipolar transistors) made from InP or GaAs?
  5. When silicon is added to GaAs to make it n-type, which site does the silicon mainly occupy?