In it we know about semiconductor diodes....

1. Semiconductor Diodes
Guided By -: Prof. R. Jaiswal
Presented By-: Jitendra Singh Tomar

2. Diode is a two terminal device having Two Semiconductor one is
P- type other one is N- type.
Depletion layer
P N
-
-
-
-
-
-
-
-
+
+
+
+
+
+
+
+
- - + +
• Positive immobile ions accumulate near junction on N side
• Negative immobile ions accumulate on P side

3. IF
vR vF
IR

4. This type of diode is widely used for rectification…..
TRCT1 2
N1
N2
N3
+
VG1
D1 1N1183
D2 1N1183
R1 1k
V +
VM1
T
0.00 25.00m 50.00m 75.00m 100.00m
Time (s)
Voltage (V)
1.00
500.00m
0.00
-500.00m
-1.00

6. Zener Diode: Symbol:
A K
A K
• A Zener Diode is a special type of properly doped crystal
diode which is designed to operate in the reverse
breakdown region.

7. The following two processes causes
junction breakdown :
1. Zener Breakdown
2. Avalanche Breakdown

8. Zener Breakdown
 Zener Breakdown observed less than 6V.
 In Zener breakdown covalent bonds break due to high electricfield.
 On Increase Temperature zener breakdown will be decrease.

9.  Avalanche breakdown observed between 6V to 200V
 Break the covalent bonds due to High K.E.
 On Increase Temperature breakdownvoltage inscrease..

11.  As a meter protection : Zener Diode widely used for
meter protection in reverse votage constant region.
+
VG1
+
A
AM1
Z1 1N2804

12.  As a Voltage regulator :
+
R1 1k
VG2
R2 1k
Z2 1N2804

13. LED: Symbol:
A K
• Light Emitting Diode (LED) is a special type of diode
emitting visible or non visible light when forward biased.
These diodes are not made from silicon or germanium
because they are heat producing materials and are not
good in emitting light radiations.

15.  LED is widely used for 7 segment
display, 16 segment display.
It is also used in alpha numeric display.
 It is also used in optical switching.
 etc..