Go through that;
Post-6 N-type Semiconductor's structure and electric conduction
By reading above two posts you understand that how P-type and N-type extrinsic semiconductor works. After that we will make the P-N Junction diode.......How..?
Let's see....
When we join the P-type semiconductor to the N-type semiconductor permanently we will get P-N Junction Diode which is shown in Fig.8a.
Fig.8a
We earlier see that N-type semiconductor consists more number of the free electrons than the P-type semiconductor, there fore "Diffusion" will occurs.
It means that the free electrons of N-type moves towards the P-type and fill the empty place in the P-type. And also we can say that the less number of holes moves towards the P-type to N-type.
These conditions shows in the Fig.8b.
Fig.8b
After that situation, at the junction P-type contains more number of aluminum ions and N-type contains more number of Arsenic ions it means that P-type and N-type consists negative and positive charge respectively.
For these charges, The electric field creates at the junction from N-type to P-type it means N-type having positive potential and P-type having negative potential. But the total potential become zero at the junction.
After that now the free electrons want to pass the junction it face the electric field which creates from N-type to P-type.
When the electric field become more powerful, the diffusion of electrons-holes will stop which shows in Fig.8c.
Fig.8c
By these process we can conclude two major things which are as follows;
[1] Junction contain two small N-type and P-type place which are not contain there majority carrier as electrons and as holes respectively. this place at the junction is known "Depletion Layer". The breadth of the depletion layer is 0.5 um.
[2] The Electric Potential creates in the depletion layer is known as "Depletion Barrier". Here it is 0.1 volts.
Note:-The Depletion Barrier and Depletion Layer in P-N Junction Diode depends upon the impurities added in to the P-type and N-type semiconductor.
Impurities less=Depletion Layer increase=Electric Field become weak
Impurities more=Depletion Layer decrease=Electric Field become high
Post-6 N-type Semiconductor's structure and electric conduction
By reading above two posts you understand that how P-type and N-type extrinsic semiconductor works. After that we will make the P-N Junction diode.......How..?
Let's see....
When we join the P-type semiconductor to the N-type semiconductor permanently we will get P-N Junction Diode which is shown in Fig.8a.
Fig.8a
We earlier see that N-type semiconductor consists more number of the free electrons than the P-type semiconductor, there fore "Diffusion" will occurs.
It means that the free electrons of N-type moves towards the P-type and fill the empty place in the P-type. And also we can say that the less number of holes moves towards the P-type to N-type.
These conditions shows in the Fig.8b.
Fig.8b
After that situation, at the junction P-type contains more number of aluminum ions and N-type contains more number of Arsenic ions it means that P-type and N-type consists negative and positive charge respectively.
For these charges, The electric field creates at the junction from N-type to P-type it means N-type having positive potential and P-type having negative potential. But the total potential become zero at the junction.
After that now the free electrons want to pass the junction it face the electric field which creates from N-type to P-type.
When the electric field become more powerful, the diffusion of electrons-holes will stop which shows in Fig.8c.
Fig.8c
By these process we can conclude two major things which are as follows;
[1] Junction contain two small N-type and P-type place which are not contain there majority carrier as electrons and as holes respectively. this place at the junction is known "Depletion Layer". The breadth of the depletion layer is 0.5 um.
[2] The Electric Potential creates in the depletion layer is known as "Depletion Barrier". Here it is 0.1 volts.
Note:-The Depletion Barrier and Depletion Layer in P-N Junction Diode depends upon the impurities added in to the P-type and N-type semiconductor.
Impurities less=Depletion Layer increase=Electric Field become weak
Impurities more=Depletion Layer decrease=Electric Field become high
God Bless Thx......
