1. Tardigrade
  2. Question
  3. Physics
  4. The electrical conductivity of a semiconductor increases when electromagnetic radiation of a wavelength shorter than 2480 nm is incident on it. The bandgap (in eV ) for the semiconductor is

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. The electrical conductivity of a semiconductor increases when electromagnetic radiation of a wavelength shorter than $2480 \, nm \, $ is incident on it. The bandgap (in $eV$ ) for the semiconductor is

NTA AbhyasNTA Abhyas 2022

Solution:

Band gap is the energy gap between conduction and valence band
Solution
For excitation of $e^{-}$ from valence band to conduction band
$E_{phton}\geq E_{g}$
$\frac{hC}{\lambda }\geq E_{g}$
$\left(\text{E}\right)_{\text{g}} = \frac{\text{1240} \text{eV}}{\lambda \text{(nm)}}$
$\text{E}_{\text{g}} = \frac{\text{1240 eV}}{\text{2480 }} = \text{0.5 } \text{eV}$