The gap between valence and conduction bands in diamond is 5.47eV.
(a) What is the maximum wavelength of a photon that can excite an electron from the top of the valence band into the conduction band? In what region of the electromagnetic spectrum does this photon lie?
(b) Explain why pure diamond is transparent and colorless.
(c) Most gem diamonds have a yellow color.
Explain how impurities in the diamond can cause this color.