A p-type semiconductor is formed by adding a III group element(such as B, Al) as a doping element.
An impurity added creates a vacancy of electrons.
For example in the above picture, The impurity atom is surrounded by four silicon atoms. It provides the atoms to make only three covalent bonds as it has only three valence electrons. The vacancy that exists in the fourth bond constitutes the hole.
This hole accepts electrons from the neighborhood. Trivalent impurities are called the acceptor impurities because each hole it contributes can accept a free electron during recombination.
In p-type semiconductors, holes are the majority carriers, and electrons are the minority carriers.
In p-type the hole density is much greater than the electron density.
The acceptor energy level of the p-type is close to the valence band and away from the conduction band.
