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Chemistry Investigatory Project

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BAL BHARTI SCHOOL, 13, KAMLA NEHRU ROAD,
CIVIL LINES, PRAYAGRAJ
ART INTEGRATED PROJECT
ART INTEGRATED PROJECT OF
PHYSICS AND CHEMISTRY
PRESENTED BY:
Mohammad Zaid Khan
CLASS 12-A3
Prakhar Gupta
ACKNOWLEDGEMENT
I WOULD LIKE TO EXPRESS MY SPECIAL THANKS TO MY
CHEMISTRY TEACHER RAVI SIR AND MY PHYSICS TEACHER
ANAND SIR AS WELL AS OUR PRINCIPLE RANJANA SRIWASTAVA
MAM WHO GAVE ME THE GOLDEN OPPORTUNITY TO DO THIS
WONDERFUL PROJECT THE ART INTEGRATED PROJECT ON
SEMICONDUCTOR AND DEVICES, WHICH ALSO HELPED ME IN
DOING A LOT OF RESEARCH AND I CAME TO KNOW ABOUT SO
MANY NEW THINGS ABOUT SEMICONDUCTOR AND DEVICES.
SECONDLY I WOULD LIE TO THANKS TO MY PARENTS AND FRIEND
WHO HELPED ME A LOT OF FINALIZING THIS PROJECT WITHIN THE
LIMITED TIME RANGE.
CONTENT
INTRODUCTION
CONDUCTORS
INSULATORS
SEMICONDUCTOR
Type of semiconductor.
Difference between intrinsic and extrinsic.
Difference between n-type and p-type semiconductors.
COMPARISON OF CONDUCTOR, INSULATOR &
SEMICONDUCTOR ON THE BASIS OF ENERGY BAND DIAGRAM
APPLICATION OF SEMICONDUCTOR
INTRODUCTION
Semiconductor devices are electronic devices with
conductivity between a good conductor and an insulator. It
uses the special electrical characteristics of semiconductor
materials to accomplish specific functions such as generate,
control, receive, transform, and amplify signals, and convert
energy. The semiconductor materials of the semiconductor
device are silicon, germanium or gallium arsenide, which can
be used as rectifiers, oscillators, light emitters, amplifiers,
photometers, and other equipment. To distinguish them from
integrated circuits, they are sometimes called discrete
devices. The basic structure of most two terminal devices
(i.e., crystal diodes) is a PN junction
CONDUCTORS
CondUctorS are materialS that permit electronS to flow freely from particle to
particle. An object made of a condUcting material will permit charge to be
tranSferred acroSS the entire SUrface of the object.
i.
Hard Drawn Copper CondUctor
ii.
Steel Cored Copper CondUctor (SCC)
iii. CadmiUm Copper CondUctor
INSULATORS
InSUlator iS a material in which electric cUrrent doeS not flow freely. The
atomS Of the inSUlator have tightly boUnd electronS which cannot readily
move. The property that diStingUiSheS an inSUlator iS itS reSiStivity.
The moSt common exampleS are non-metalS.
SEMICONDUCTOR
A SEMICONDUCTOR IS A MATERIAL THAT HAS INTERMEDIATE
CONDUCTIVITY BETWEEN A CONDUCTOR AND INSULATOR . SILICON
AND GERMANIUM ARE THE EXAMPLES OF SEMI CONDUCTORS THE
MAGIC WORD SEMICONDUCTOR IS COMPOSED OF TWO WORDS SEMI &
CONDUCTOR SEMI MEANS NOT COMPLETELY WHILE CONDUCTOR
MEANS SOMETHING, WHICH CAN CONDUCT ELECTRICITY
INTRINSIC
SEMICONDUCTOR
THE PURE SEMICONDUCTOR (IMPURITY LESS THAN 1 PART IN 10 )
ARE CALLED INTRINSIC SEMICONDUCTOR.
EXTRINSIC
SEMICONDUCTOR
A SEMICONDUCTOR DOPED WITH SOME SUITABLE IMPURITY ATOMS SO AS
TO INCREASE ITS NUMBER OF CHARGE IS CALLED AN EXTRINICS
SEMICONDUCTOR.
TYPES OF EXTRINSIC
SEMICONDUCTOR
DIFFERENCE BETWEEN EXTRINSIC
AND INTRINSIC CONDUCTOR
S.NO
Intrinsic Semiconductor
Extrinsic Semiconductor
1.
Semiconductor in a pure form is called
Intrinsic semiconductor.
Semiconductor which are doped with impurity
is called extrinsic semiconductor.
2.
Here the change carriers are produced
only due to thermal agitation.
Here the change carries are produced due to
thermal agitation.
3.
They have low electrical conductivity.
They have high electrical conductivity.
4.
They have low operating temperature.
They have high operating temperature.
5.
At 0K, Fermi level exactly lies between
conduction band and valence band.
At 0K, Fermi level exactly lies closer to
conduction band in “n” type semiconductor
and lies near valence band in “p” type
semiconductor.
Example: Si, Ge, etc.
Example: Si and Ge doped with AI, In, P ,As
etc.
DIFFERENCE BETWEEN N-TYPE AND
P-TYPE SEMICONDUCTOR
S.NO
N-Type Semiconductor
P-Type Semiconductor
1.
N-type semiconductor is obtained by
doping and intrinsic semiconductor with
pentavalent impurity.
P-type semiconductor is obtained by doping
and intrinsic semiconductor with trivalent
impurity.
2.
Here electrons are majority carries and
holes are minority carriers.
Here holes are majority carries and electrons
are minority carriers.
3.
It has donor energy levels very close to
CB.
It has acceptor energy levels very close to VB.
4.
When the temperature is increased
these semiconductors can easily donate
and electron from donor energy level to
the CB.
When the temperature is increased, these
semiconductor can easily accept an electron
from VB to donor energy level.
COMPARISONOF CONDUCTORS, INSULATORS
SEMICONDUCTOR ON THE BASIS OF ENERGY BAND DIAGRAM
APPLICATION OF
SEMICONDUCTORS
Semiconductors are of great importance in electronics industry.
Various combinations of n-type & p-type Semiconductors are
used for making different types of electronic components , e.g.,
diodes, transistors, integrated circuits (IC’s),etc. Diode which is
used as a rectifier is a combination of n-type and p-type
Semiconductors. Transistors are prepared by sandwiching a
layer of one type of semiconductor between two layers of the
other type of semiconductors
DIODE
A diode is a semiconductor device that essentially acts as a oneway switch for current. It allows current to flow easily in one
direction, but severely restricts current from flowing in the
opposite direction.
Diode-:
“Biased p-n junction” , i.e. p-n junction
with voltage applied across it.
“Forward biased”: p-side more positive
than n- side.
“Reverse biased”: n-side more positive
than p-side.
p -n JUNCTION DIODE
A diode is a semiconductor device that essentially acts as a oneway switch for current. It allows current to flow easily in one
direction, but severely restricts current from flowing in the
opposite direction.
BIASING OF DIODE
i.
Forward biasing
ii. Reverse biasing
FORWARD BAISING
Forward biasing means putting a voltage across a diode
that allows current to flow easily.
The direction of electric field is from p-side towards n-side.
p-type charge carries (positive holes) in p-sides are pushed
towards and across the p-n boundary.
n-type carries (negative electrons) in n-side are pushed towards
and across n-p boundary.
Current flows across p-n boundary.
REVERSE BIASING
Reverse biasing means putting a voltage across a diode in the
opposite direction. The voltage with reverse biasing doesn't
cause any appreciable current to flow.
DIFFERENCE BETWEEN FORWARD
BIASING AND REVERSE BIASING
Forward Biasing
Reverse Biasing
o Positive terminal of battery is
connected to p-type and negative
to n-type semiconductor.
o Positive terminal of battery
connected to n-type and negative
terminal to p-type semiconductor.
o Depletion layer is very thin.
o Depletion layer is thick.
o P-n junction offers very low
resistance.
o P-n junction offers very high
resistance.
o An ideal diode have zero
resistance.
o An ideal diode have infinite
resistance.
USES OF DIODE
HALF WAVE RECTIFIER
A half wave rectifier is defined as a type of rectifier that only
allows one half-cycle of an AC voltage waveform to pass,
blocking the other half-cycle. A rectifier is a device that
converts alternating current (AC) to direct current (DC).
It is done by using a diode or a group of diodes.
FULL WAVE RECTIFIER
Full-wave rectification rectifies the negative component of the
input voltage to a positive voltage, then converts it into DC
(pulse current) utilizing a diode bridge configuration. In
contrast, half-wave rectification removes just the negative
voltage component using a single diode before converting to
DC.
DIFFERENCE BETWEEN HALF WAVE
AND FULL WAVE RECTIFIER
Full-Wave Rectification
Circuit Configuration
Input Voltage Waveform
Voltage Waveform After
Rectification
Voltage Waveform After
Rectification Smoothing
Half-wave Rectification
TYPES OF DIODE
PHOTO DIODE
A photodiode is a semiconductor p-n junction device that
converts light into an electrical current. The current is
generated when photons are absorbed in the photodiode.
Photodiodes may contain optical filters, built-in lenses, and
may have large or small surface areas.
SOLAR CELL
A solar cell, or photovoltaic cell, is an electrical device that
converts the energy of light directly into electricity by the
photovoltaic effect, which is a physical and chemical
phenomenon
REFERENCE
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