Q.No.214: - Why germanium is more unstable at high temperature and why silicon is widely used than germanium?

Q.No.214: - Why germanium is more unstable at high temperature and why silicon is widely used than germanium?

Ans: - The valence electrons in germanium are in the fourth shell while those in silicon are in the third shell, closer to the nucleus. This means that the germanium valence electrons are at high energy levels than those in silicon and therefore, require a smaller amount of additional energy to escape from the atom. This property makes germanium more unstable at high temperatures and results in excessive reverse current. This is why silicon is a more widely used semi-conductive material.