PIN Diode presentation physics presentation.pdf

this is the presentation of pin diode

1. PIN Diode

2. What is PIN Diode?
oA PIN Diode can be defined as :
A diode with a wide and undoped
intrinsic semiconductor region between a P-
type and N-type semiconductor.

3. The PIN diode was first used in the year 1952 as a
low frequency and high power rectifier. It was even
used for microwave applications and as a
photodetector as it is said to be a good light
absorber.
A PIN diode is a type of diode having
undopedintrinsic semiconductorregion placed
between two regions called p-type semiconductor
and the n-type semiconductor region. These two
regions are primely heavily doped as they find
applications for ohmic contacts

4. Characteristics of PIN photodiode :
Some of the PIN Diodecharacteristics are given in the
points below.
➢The capacitance of PIN diode is independent of bias
level as the net charge is said to be very less in the
intrinsic layer.
➢PIN diode possesses very low reverse recovery time.
➢The Diode obeys the standard diode equation for all the
low-frequency signals.
➢This diode appears more like a resistor than any other
non-linear device and is said to produce no distortion or
rectification.

5. Structure and Working of a Pin Diode
The PIN diode comprises a
semiconductor diode having three
layers naming the P-type layer,
Intrinsic layer and N-type layer, as
shown in the figure below. The P
and N regions are there, and the
region between them consists of
the intrinsic material, and the
doping level is said to be very low
in this region. The thickness of the
intrinsic layer is very narrow, which
ranges from 10 – 200 microns. The
P region and the N-type regions
are known to be heavily doped.

6. Zero Biased:
➢In the absence of an external voltage (battery), the P-type and N-type semiconductor
layers in the PIN photodiode remain electrically neutral.
➢Electrons in the N-type layer and holes in the P-type layer are evenly distributed.
➢When light strikes the Intrinsic layer, electron-hole pairs are generated.
➢The generated electrons and holes are subject to the internal electric field created by
the inherent potential difference between the P and N layers.
➢Due to the electric field, electrons move towards the N-type layer, and holes move
towards the P-type layer.
➢This migration of charge carriers creates an area depleted of carriers in the Intrinsic
layer.
➢The region depleted of charge carriers is known as the depletion region.
➢Within this region, there is a net charge separation: positive charges (holes)
accumulate near the N-type layer, and negative charges (electrons) accumulate near
the P-type layer

7. Reverse Biased:
➢In the reverse-biased condition, an external voltage is applied in such a way that
the P-type layer is connected to the negative terminal, and the N-type layer is
connected to the positive terminal.
➢The external voltage enhances the existing internal electric field, causing the
depletion region to widen in the Intrinsic layer.
➢The wider depletion region extends further into the Intrinsic layer.
➢With the reverse bias, the potential barrier height between the P and N layers
increases.
➢This increased barrier height hinders the movement of majority carriers (holes in
P-type and electrons in N-type) across the junction.
➢The wider depletion region and increased potential barrier lead to a significant
reduction in the flow of charge carriers.

8. Forward Biased:
➢In the forward-biased condition, an external voltage is applied in such a way that
the P-type layer is connected to the positive terminal, and the N-type layer is
connected to the negative terminal.
➢The external voltage reduces the existing internal electric field, causing the
depletion region in the Intrinsic layer to contract.
➢The narrowed depletion region allows for a free movement of charge carriers.
➢With the forward bias, the potential barrier height between the P and N layers
decreases.
➢The reduced barrier height facilitates the movement of majority carriers (holes in
P-type and electrons in N-type) across the junction.
➢The narrowed depletion region and reduced potential barrier lead to a significant
increase in the flow of charge carriers.
➢In the forward-biased state, the PIN photodiode becomes more sensitive to
incident light.
➢The increased current flow allows for a higher response to the photogenerated
carriers

9. Applications ofPIN Diode
➢Thesediodesare used in the RF and also for
microwave switches and microwave variable
attenuators since they are said to have low
capacitance.
➢They are used in Photodetectors and photovoltaic
cells, and the PIN photodiodes are used for fiber
optic network cards and switches.
➢These diodes are effectively used for RF protection
circuits, and they can also be utilized as an RF
switch.
➢The PIN photodiode is also used to detect X-rays
and gamma rays photons.

10. The END