A $p-n$ photodiode is fabricated from a semiconductor with a band gap of 2.5 eV . It can detect a si

Question

A $p-n$ photodiode is fabricated from a semiconductor with a band gap of 2.5 eV . It can detect a signal of wavelength\

Professor PC Thomas Classes · Answer

(c): Band gap $=2.5 \mathrm{eV}$ The wavelength corresponding to 2.5 eV 
$ =\frac{12400 \mathrm{eV} \AA}{2.5 \mathrm{eV}}=4960 \AA $
 $4000 \AA$ can excite this.\