Question

In a semiconductor at room temperature
A. the valence band is partially empty and the conduction band is partially filled
B. the valence band is partially empty and the conduction band is partially filled
C. the valence band is completely filled
D. the conduction band is completely empty

Answer 1

Hint: The above problem is resolved by using the valence band's concepts and the conduction band in the semiconductor. The concept of electron excitation from the lower energy state to higher energy also applied along with these. The electronic excitation occurred when energy was given to the lower energy state's electrons, which jumped to the accumulation's higher energy state.

Complete step by step solution:
We know that the electrons tend to absorb the given amount of energy to excite higher energy levels. Similarly, semiconductors possess some electrons in their valence band. And at room temperature, some of these electrons gain a little part of the energy to undergo excitation from the valence band to the conduction band. But the other electrons remain in the valence band.

Therefore, the valence band is partially empty, and the conduction band is partially filled, and option (A) is correct.

Note: To resolve the given problem, one must understand the valence band's basic concepts and applications and the conduction band. The valence band is that energy level, in which the electrons reside even at the temperature of the absolute zero. On the other hand, the conduction band is the vacant energy level, which is generally occupied by the electrons after the excitation. The excitation of electrons occurs due to the magnitude of energy supplied to electrons, such that it gets jumped from the preceding state to a new energy state.