Quiz: Conductors, semiconductors, insulators and p-n junctions

Solids can be categorised into conductors, semiconductors or insulators by their ability to conduct electricity. Electron band theory explains differences in conduction.

Semiconductors can be doped with other materials to become p-type or n-type. A p-n junction diode can be forward or reverse bias. LEDs are forward bias diodes that produce photons of light. Solar cells are p-n junctions that absorb photons, giving electrons enough energy to enter the conduction band.