1. Tardigrade
  2. Question
  3. Physics
  4. An LED is constructed from a p-n junction based on a certain Ga-As -P semiconducting material whose energy gap is 1.9 eV. What is the wavelength (in nm) of the emitted light?

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. An LED is constructed from a $p-n$ junction based on a certain $Ga-As -P$ semiconducting material whose energy gap is $1.9 \,eV$. What is the wavelength (in nm) of the emitted light?

Semiconductor Electronics: Materials Devices and Simple Circuits

Solution:

If $\lambda$ is the wavelength of emitted light, then
$E_g = \frac{hc}{\lambda}$
or $\lambda = \frac{hc}{E_g}$
$ = \frac{(6.63 \times 10^{-34}) \times ( 3 \times 10^8)}{(1.9) \times (1.60 \times 10^{-19})}$
$ = 6.5 \times 10^{-7} \,m = 650\,nm$