Résumé
This chapter explores the elements required to bridge semiconductor and metal sciences with electromagnetism. For semiconductors as well as metals, susceptibilities are complex quantities, exhibit a spectral dependence, and exhibit resonances centered at energies specific to the chemical element(s) assembled to form the crystal. In terms of conductivity, gold and diamond are highly different. Gold is a metal, while diamond is an insulator. Diamond is transparent, while gold is not. Diamond is a good conductor of heat, like gold. There are two great families of Bravais lattices for technologically impacting semiconductors: the face-centered cubic lattice and the hexagonal one. Gallium arsenide is most commonly grown as a zinc blende crystal, such as InP or GaSb, two other interesting binary compounds obtained by assembling group III and group V elements. When a solid is shined by an electromagnetic radiation, part of this radiation is reflected, part of it is transmitted, part of it is absorbed, and part of it is scattered.