Question

If the energy gap of a semiconductor is 1.1 e V it would be:

• A. Transparent to the ultraviolet radiation
• B. Opaque to the visible light
• C. Transparent to the visible light
• D. None of these

Answer 1

The correct option is B Opaque to the visible light

Visible light lies in the range of about 2.0 eV to 3.2 eV on the electromagnetic spectrum.

This energy is sufficient to excite the valence electrons in the semiconductor and is hence absorbed by it.

As a result, photons of lower energy are emitted which do not fall in the visible range of light.

This causes the opacity of the semiconductor to visible light.