Light-emitting diodes are semiconductors that emit light when a current is passed through them. What is the key factor that must be changed to change the wavelength of the emitted light in an LED?
A)the width of the valence band
B)the width of the conduction band
C)the width of the band gap
D)the magnitude of the current
E)the type of semiconductor (p vs.n)

Question

Quizplus · Accepted Answer

The wavelength of the emitted light is determined by the width of the band gap in the semiconductor material. As the width of the band gap changes, the energy levels of the electrons in the valence and conduction bands also change, leading to a different wavelength of emitted light. Changing the width of the valence and conduction bands, the magnitude of the current, or the type of semiconductor would not have a direct effect on the wavelength of the emitted light.

Light-Emitting Diodes Are Semiconductors That Emit Light When a Current