1. P-N Junction Diode
Presented by:
PANKAJ
B .Tech (2nd year)
1906950310035
Department of Electronics and
Communication Engineering
SHRI RAM GROUP OF COLLEGE
MUZAFFARNAGAR
2. Contents
• What is PN junction
a. N-type semiconductors
b. P-type semiconductors
• depletion region
• Biasing of a diode
a. Types of biasing
• Working of PN junction diode
• V-I characteristics of PN junction diode
• advantages
3. What is P-N JUNCTION?
P-N TYPE JUNCTION:
• When P -type semiconductor is joined to
N –type semiconductor, the contact
surface is called P-N Junction.
• It is made up of one n-type material and
one p-type material and both are doped
with some other materials.
4. N-Type Semiconductor
• N- Type : When a small amount of Penta-
Valent impurity is added to a pure
semiconductor, it’s known as a N- Type
semiconductor.
Figure 1: Doped trivalent
Ge with Pentavalent As.
When we are doped trivalent Ge
with pentavalent As, It contains
free electrons.
5. P-Type Semiconductors
• P-type : when a small amount of Trivalent
impurity is added to a pure semiconductors ,
it’s called P-type semiconductors.
Figure 2:Si doped with Boron
Si is Tetravalent and is doped with the
Trivalent Boron (B) and it contains
Holes.
6. Depletion Region
Depletion Region: Depletion region is also called depletion layer ,depletion zone
The combining of electrons and holes depletes the holes in the P-region and the electrons
in the N-region near the junction.
Figure 1: Depletion Region & Depletion Layer ,Barrier potential
Barrier potential for the Si is 0.7V and for the Ge is the 0.3V
7. Biasing a PN-Junction Diode
• Biasing means giving electrical potential to the
diode.
• There are two types of biasing in diodes. And
it depends on the polarity of the voltage
applied to the diode.
1. Forward Biasing
2. Reverse Biasing
10. ADVANTAGES
• No filament in necessary. In case of light
emitting diode(LED).
• Occupies lesser space as compared to other
lighting devices such as fluorescent lamp, CFL
etc.
• Long life. As less heat is generated during
operation as compared to others.
11. Any doubts or questions?
All suggestions are most
welcome.