To a germanium sample, traces of gallium are added as an impurity. The resultant sample would behave like

Options

A. A conductor
B. A p-type semiconductor
C. An n- type semiconductor
D. An insulator

Answer

B

Explanation

An intrinsic germanium have four outer electrons which they use to form bonds with four neighbouring Ge atoms. Gallium, being from group III is having three outer electrons. So when we add gallium atoms into germanium, some gallium atoms have a chance to replace some of the germanium atoms . But with bonds with Ga. The Bond with the fourth neighbouring outer electron. The broken bond can be filled up by an electron when the electron gets enough energy to jump from the valence bond creating a hole out there. So, we get a P-type semiconductor.