Indicate if each solid forms an n-type or a p-type semiconductor. a. germanium doped with gallium b. silicon doped with arsenic

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everyone in this example, we're told that silicon is doped with boron. We need to determine whether this substance is going to be an N. Type or a P type semiconductor. So first considering our silicon crystal, we want to recall that on our periodic table. Silicon can be, can be found in group four a. And we recall that the group number corresponds to the number of valence electrons, meaning that we would have a total of four valence electrons. Now when we consider boron we recall that boron on our periodic tables is located in group three a. And that corresponds to three valence electrons. We want to also recognize that based on the positions of these two atoms on the periodic table, Silicon is going to be considered a nonmetal and boron is going to be considered a metal Lloyd. And we want to recall that non medals will not conduct electricity well. Whereas our metal lloyds are considered semi conductors of electricity. So what we want to imagine is our atom of silicon. And recall that again, it has four valence electrons. So we're going to draw those in as these dots here and recall that it's going to use its valence electrons to form Covalin bonds with other atoms. And because it has four valence electrons, it's going to form four Covalin bonds with other atoms. So we can just imagine those other atoms as silicon forming our silicon crystal. Now let's imagine our boron and recall that we said that it has three valence electrons. So we're going to draw in those three valence electrons. And so that means it would form three covalin bonds with other atoms. So in this case since we are doping our silicon with boron, we would make three Covalin bonds to three other silicon atoms. However, we should recognize that as we stated, Silicon wants to make four bonds because it has four valence electrons. And because boron only has three valence electrons, we have a hole here where our fourth silicon atom would want to form a bond here but it can't because we don't have 1/4 available electron valence electron from boron. And so this here is our whole which we can also recall would represent so sorry, this says hole and this represents a vacancy an electron vacancy due to the fact that we can't form this fourth bond to another silicon atom. And so because this hole here is present, since we recall that boron is a metal Lloyd and a semi conductor of electricity, this hole is therefore going to be free to move in the conduction band of electricity. And it's the free movement of this whole that forms in our crystalline of silicon doped with boron that carries the electrical charge and is therefore labeled as a P type semiconductor. So this would be our final answer to complete this example when we have our silicon crystalline doped with boron, we would form a P type semiconductor. So I hope that everything I explained was clear. If you have any questions, please leave them down below and I will see everyone in the next practice video.

Indicate if each solid forms an n-type or a p-type semiconductor. a. germanium doped with gallium b. silicon doped with arsenic

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