The gap between the valence and conduction bands of a certain semiconductor is 0.85eV.When this semiconductor is used to form a light emitting diode, the wavelength of the light emitted: A)is in a range above 1.5 * 10^-6 m B)is in a range below 1.5 *10^-6 m C)is always 1.5 *10^-6 m D)is in a range centered on 1.5 *10^-6 m E)has nothing to do with the gap

Question

Quizplus · Accepted Answer

The wavelength of light emitted by a semiconductor in a light emitting diode (LED) is directly related to the energy gap between the valence and conduction bands. The energy of the emitted photon (in eV) is approximately equal to the band gap energy. Using the equation $E = \frac{hc}{\lambda}$, where $E$ is the energy in eV, $h$ is Planck's constant, $c$ is the speed of light, and $\lambda$ is the wavelength in meters, we can calculate the wavelength of the emitted light. Given the band gap of 0.85eV, the wavelength will be in the infrared or near-infrared range, which is below 1.5 micrometers ($1.5 \times 10^{-6}$ m), indicating that choice B is correct.

The Gap Between the Valence and Conduction Bands of a Certain