How the N and P types of diodes are formed

N-type semiconductors DIODE: Intrinsic semiconductors are doped with pentavalent impurity elements, such as phosphorus, to form N-type semiconductors, also known as electronic semiconductors. Because only four valence electrons in the pentavalent impurity atom can form with the valence electrons in the surrounding four semiconductor atoms

Covalent bonds, and the extra one valence electron can easily form free electrons due to the absence of covalent bond binding. Since it is electrons that are involved in conducting electricity, which are negatively charged, they are called N-type semiconductors DIODE.

The doping of 3-valent impurity elements, such as boron, into intrinsic semiconductors can form P-type semiconductors, also known as hole-type semiconductors DIODE. Because only 3 valence electrons in the 3-valent impurity atom can form a covalent bond with the valence electrons in the surrounding 4 semiconductor atoms, it is still less

Only 1 valence electron can form a stable covalent bond, and this situation of one less valence electron is called a hole, that is, the hole of a P-type semiconductor DIODE is many, and the free electron is a few, and it mainly conducts electricity by holes. Since it is a hole that conducts electricity, it is positively charged.