Question

The band gap between the valence and the conduction bands in zinc oxide (ZnO) is 3.2 eV. Suppose an electron in the conduction band combines with a hole in the valence band and the excess energy is released in the form of electromagnetic radiation. Find the maximum wavelength that can be emitted in this process.

Answer 1

Explanation:

It is given that:

Gap in band = 3.2 eV

In the conduction band, the electron links with the valence band’s hole. There will be a minimum energy band gap due to the release of maximum energy via which the jumping electron will be equal to the material’s band gap.

This shows that the extreme energy unrestricted in this method will be equal to the material’s band gap.

Here, $E=3.2 \mathrm{eV}$

So, $3.2 \mathrm{eV}=1242 \mathrm{eV}-\mathrm{nm} \lambda$

⇒Wavelength$(\lambda)=388.1 \mathrm{nm}$