If a semiconductor photodiode can detect a phonon with a maximum wavelength of 400 nm , then its ban

Question

If a semiconductor photodiode can detect a phonon with a maximum wavelength of 400 nm , then its band gap energy is \  Plank's constant  $h=6.63 	imes 10^{-34} \mathrm{~J} \mathrm{~s}$ \ Speed constant $ c=3 	imes 10^8 \mathrm{~m} / \mathrm{s} $

Professor PC Thomas Classes · Answer

$E = \frac{hc}{\lambda} = \frac{1240 	ext{ eV}\cdot	ext{nm}}{400 	ext{ nm}} = 3.1$ eV.