What Bandgap Energy Range is Required for Blue LEDs?

[aChordate]

Homework Statement

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?

Homework Equations

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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.

 

[CWatters]

Relevant Equations..

Frequency = velocity * wavelength
Energy = Planck const * frequency

 

[ehild]

Relevant Equations..

Frequency = velocity * wavelength

Frequency = speed / wavelength

ehild

 

[CWatters]

Oops yes that's right.

Velocity = frequency * wavelength
so
frequency = Velocity/wavelength