Physics 2000 JAMB Past Questions - Question 39: in a pure semiconductor, the number of electrons - the conduction band is

Correct Answer

A

Explanation

In a pure semiconductor, the number of electrons in the conduction band is typically very low at absolute zero temperature because all the electrons are in the valence band. A semiconductor is an intrinsic semiconductor when it is pure and not intentionally doped with other atoms to increase its conductivity. in a pure semiconductor, the number of electrons - the conduction band is

At absolute zero (0 Kelvin or -273.15 degrees Celsius), the valence band of a semiconductor is fully occupied by electrons, and the conduction band is empty. This is because the electrons in the valence band have the lowest energy levels and are tightly bound to the atomic lattice.

As you increase the temperature, some electrons gain enough thermal energy to transition from the valence band to the conduction band, creating charge carriers (both electrons and holes) in the conduction band. The exact number of electrons in the conduction band at any given temperature depends on the material's bandgap energy, the temperature, and other factors.

So, the number of electrons in the conduction band in a pure semiconductor increases with temperature due to thermal excitation, and it depends on the specific semiconductor material and its properties.