Which type of semiconductor has 5 valence electrons in its outer shell?

The type of semiconductor that has 5 valence electrons in its outer shell is indeed the N-type semiconductor. N-type semiconductors are typically formed by doping a pure semiconductor, such as silicon or germanium, with elements that have five valence electrons. A common dopant for N-type semiconductors is phosphorus, which has five valence electrons, allowing for an increase in the number of free electrons available for conduction.

In N-type semiconductors, the additional electrons from the dopant atoms are not bound to the atom and can move freely, contributing to electrical conductivity. This extra electron is available for conduction, making N-type semiconductors negatively charged since these free electrons outnumber the holes that result from absent electrons.

In contrast, P-type semiconductors are made by doping with elements that have three valence electrons, leading to “holes” that can also carry charge but do not provide extra electrons. Conductors and insulators do not fit within this framework as conductors have high conductivity typically due to free electrons without doping, and insulators do not typically have free-moving charge carriers.