Below the reflection spectra for two materials A and B are given.
(a) What type of material belongs to reflection spectrum A, what type to B? (Justify). Note the scale difference!
(b) For which colors are these (bulk) materials transparent?
(c) What is the approximate threshold energy for interband transitions for these materials?
(d) For which of the materials would you expect intraband transitions in the infrared region? (Justify.)
(e) Why do these intraband transitions occur in this region?
