We all know that the material which is semiconductor having two types which follows as
[1] intrinsic semiconductor and
[2] extrinsic semiconductor.
For the understanding of intrinsic type semiconductor please visit below post;
[1] intrinsic semiconductor and
[2] extrinsic semiconductor.
For the understanding of intrinsic type semiconductor please visit below post;
Post-3 How Silicon or Germanium is working as an Semiconductor ?
For the understanding of extrinsic donor semiconductor please visit below post;
For the understanding of extrinsic donor semiconductor please visit below post;
Post-6 N-type Semiconductor's Structure and Electric Conduction
Now we come to the point and explain that what is the extrinsic acceptor semiconductor type; what is the meaning of 'P'; and what is the structure and its electric conduction.
First note that when we add any impurities in the intrinsic material then after these material becomes 'Extrinsic material' and the process of adding impurities is called "Doping".
Ex. Tetra-valent silicon will contain tri-valent impurities which are aluminum, Gallium and Indium.
As shown in Fig.7a, when a Gallium atom is added to the silicon lattice, there are three valence electrons will construct three co-valent bonds with the valence electrons of three neighboring silicon atoms.
Now we come to the point and explain that what is the extrinsic acceptor semiconductor type; what is the meaning of 'P'; and what is the structure and its electric conduction.
First note that when we add any impurities in the intrinsic material then after these material becomes 'Extrinsic material' and the process of adding impurities is called "Doping".
Ex. Tetra-valent silicon will contain tri-valent impurities which are aluminum, Gallium and Indium.
As shown in Fig.7a, when a Gallium atom is added to the silicon lattice, there are three valence electrons will construct three co-valent bonds with the valence electrons of three neighboring silicon atoms.
Fig.7a
The fourth co-valent bond consists one valence electron but that place remains empty and create 'hole' represented by a small circle in Fig.7a.
A hole is positively charged as it represents the absence of a negative charge. thus because each tri-valent impurity atom added, a hole is created which always attract electron for its empty place circle. this type is called extrinsic acceptor impurities which shown in Fig.7b.
If we notice for whole lattice, there are more number of holes are established in the P-type semiconductor. And it is possible to control the number of holes by controlling the 'Doping Concentration'.
A large number of holes are present along with a small number of thermally generated electrons in a P-type semiconductor material. That's why the holes are called "Majority charge carrier" and the electrons are called "Minority charge carrier".
Fig.7c
Then after we talk about electric conduction, when an external DC voltage is applied to the P-type semiconductor material, the holes(called Majority charge carrier) move towards to the negative terminal of the battery and the electrons(called Minority charge carrier) move towards the positive terminal of the battery which indicated in Fig.7c.
God Bless Thx......
The fourth co-valent bond consists one valence electron but that place remains empty and create 'hole' represented by a small circle in Fig.7a.
A hole is positively charged as it represents the absence of a negative charge. thus because each tri-valent impurity atom added, a hole is created which always attract electron for its empty place circle. this type is called extrinsic acceptor impurities which shown in Fig.7b.
Fig.7b
If we notice for whole lattice, there are more number of holes are established in the P-type semiconductor. And it is possible to control the number of holes by controlling the 'Doping Concentration'.
A large number of holes are present along with a small number of thermally generated electrons in a P-type semiconductor material. That's why the holes are called "Majority charge carrier" and the electrons are called "Minority charge carrier".
Fig.7c
Then after we talk about electric conduction, when an external DC voltage is applied to the P-type semiconductor material, the holes(called Majority charge carrier) move towards to the negative terminal of the battery and the electrons(called Minority charge carrier) move towards the positive terminal of the battery which indicated in Fig.7c.
God Bless Thx......
