Question

Suppose the energy liberated in the recombination of a hole-electron pair is converted into electromagnetic radiation. If the maximum wavelength emitted is 820 nm, what is the band gap ?

Answer 1

Given $\lambda =820mn$

$E=\frac{hc}{\lambda }=\frac{1242}{820}\frac{eV-nm}{nm}$

$=1.5eV$