Physics Question on Semiconductor electronics: materials, devices and simple circuits

Question

The electrical conductivity of a semiconductor increases when electromagnetic radiation of wave length shorter than $2480\, nm$ is incident on it. The band gap (in $eV$ ) for semiconductor is

Answer 1

Solution

$E_{g} = \frac{hc}{\lambda}$ $= \frac{1240\, eV \,nm}{2480\, nm}$ $= 0.5 \,eV$