p-type semiconductor
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Think of a nearly full parking garage where cars can only inch forward into an empty space. The cars are electrons; the rare empty spaces are holes. When a car rolls into a gap, the gap effectively moves backward. A p-type semiconductor carries current mostly through these moving gaps.
You make p-type material by doping a pure crystal with acceptor atoms — impurities that are short one bonding electron and so create empty bonds, or holes. Each hole acts like a free, positively charged particle that drifts through the crystal as electrons shuffle to fill it. Because the holes vastly outnumber the free electrons, holes are the majority carriers here, and the 'p' stands for positive.
p-type material is the partner to n-type; placing the two against each other forms the p-n junction at the heart of every diode, transistor, and solar cell. A frequent confusion: holes do not move because some positive object is being pushed along. They move because the surrounding electrons rearrange — the hole is the empty seat that appears to travel as people slide over, yet it responds to electric fields exactly as a real positive carrier would.
Silicon doped with boron is the textbook p-type material. Each boron atom takes an electron from a neighboring bond, leaving a hole, so the crystal conducts mainly through holes drifting in the valence band.
Boron-doped silicon: holes are the majority carriers.
Like n-type material, p-type still contains a few minority electrons from thermal excitation. The labels n and p describe which carrier dominates, not the total charge — both kinds of doped material are electrically neutral.