If you want to make a blue LED, what is the range of possible band gaps that your semiconductor must have in units of eV? Name at least one semiconductor that has a band gap in this range, it can be either an elemental or a compound semiconductor. Solution blue light has a wavelength ranging form 450 nm to 500 nm the band gap of the semiconductor required to emit blue light is given by energy = hC / wavelength So, it is 2.48 eV to 2.75 eV the range of possible bandgaps is 2.48 eV to 2.75 eV Few semiconductors that has a band gap in this range and are being used for blue LED\'s are Zinc selenide (ZnSe) Indium gallium nitride (InGaN) Silicon carbide (SiC) as substrate .

1. If you want to make a blue LED, what is the range of possible band gaps that your
semiconductor must have in units of eV? Name at least one semiconductor that has a band gap in
this range, it can be either an elemental or a compound semiconductor.
Solution
blue light has a wavelength ranging form 450 nm to 500 nm
the band gap of the semiconductor required to emit blue light is given by
energy = hC / wavelength
So, it is 2.48 eV to 2.75 eV
the range of possible bandgaps is 2.48 eV to 2.75 eV
Few semiconductors that has a band gap in this range and are being used for blue LED's are
Zinc selenide (ZnSe)
Indium gallium nitride (InGaN)
Silicon carbide (SiC) as substrate