Doped silicon is electrically neutral, whether n-type or p-type
The n and the p only say which kind of charge can move through it.
Veritasium · How Does a Transistor Work?Doped silicon, whether n-type or p-type, has as many electrons as protons, so it has no net charge.
Pure silicon is a poor conductor because each atom locks its four outer electrons into bonds with four neighbors, leaving few free to travel through the crystal. Engineers improve it by doping, or slipping in a tiny amount of a different atom.
To make n-type silicon, they add phosphorus, which has five outer electrons and fits into the crystal while adding one loose electron. To make p-type silicon, they add boron, which has only three outer electrons and leaves a hole where an electron should be. Although it is electrons that move into holes, physicists talk about the holes moving, because there are far fewer of them, and a missing electron acts as a positive charge.
In each case the material stays neutral because electrons and protons remain balanced. The n and the p name only the sign of the charge that can move, negative electrons in n-type and positive holes in p-type.
Questions people ask
Why use phosphorus and boron for doping?
Phosphorus has one more outer electron than silicon, and boron has one fewer. That makes them close enough in size and chemistry to slip into silicon's crystal without breaking it, while changing the number of mobile charges by one per atom.
How much dopant is actually added?
Very little: typically only one atom in millions is replaced. That tiny addition creates enough free electrons or holes to make the silicon conduct much better, while keeping the crystal structure intact.
If the material is neutral, how does it help carry current?
Neutrality matters because current flows only when charges move in response to voltage. Since the doped crystal starts neutral, engineers can control where electrons gather or drain away, and that control is what lets a transistor switch on and off.