Picture (1)shows the electron populations of the bands of MO energy levels for elementary silicon.
-Which picture (1)-(4)shows the electron populations when the silicon is doped with gallium?
A)picture (1)
B)picture (2)
C)picture (3)
D)picture (4)

Question

Picture (1)shows the electron populations of the bands of MO energy levels for elementary silicon. 
-Which picture (1)-(4)shows the electron populations when the silicon is doped with gallium?
A)picture (1) 
B)picture (2) 
C)picture (3) 
D)picture (4)

Quizplus · Accepted Answer

Gallium is a trivalent element, meaning it has three valence electrons. When silicon, which has four valence electrons, is doped with gallium, it creates "holes" in the crystal lattice because gallium lacks the fourth electron to complete the bond with neighboring silicon atoms. This results in p-type semiconductor material, characterized by the presence of holes as the majority charge carriers. Picture (3) should illustrate this scenario, showing an incomplete bond or a "hole" in the lattice structure.

Picture (1)shows the Electron Populations of the Bands of MO