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Blue LED bandgap energies

  1. Jul 9, 2013 #1
    1. The problem statement, all variables and given/known data

    Blue light corresponds to free space wavelengths of approximately 450 to 495 nm. If we want to use a semiconductor to make a blue LED, what range of energies must the semiconductor's bandgap fall within? Express your answer in units of electron volts(eV). What is an example of a real semiconductor with a bandgap in this range?


    2. Relevant equations

    ?

    3. The attempt at a solution


    Can someone lead me in the right direction? From what I've read, blue light LED are high energy and the whole notion of bandgap energies confuses me.
     
  2. jcsd
  3. Jul 10, 2013 #2

    CWatters

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    Relevant Equations..

    Frequency = velocity * wavelength
    Energy = planck const * frequency
     
  4. Jul 10, 2013 #3

    ehild

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    Frequency = speed / wavelength

    ehild
     
  5. Jul 10, 2013 #4

    CWatters

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    Oops yes that's right.

    Velocity = frequency * wavelength
    so
    frequency = Velocity/wavelength
     
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