Name: Kartik S Hase
Roll Number: 20CHE135
Branch: FYCE
Date: 27/02/2021
Hall Effect
AIM:
To determine for a given semiconductor sample:
1. Hall Coefficient.
2. Type of charge carriers.
3. Concentration of the charge carriers.
APPRATUS:
1. Hall probe(0.5mm)
2. Constant current source (CCS) {With voltage and ammeter}
3. DC Regulated Power Supply (DCRS)
4. Digital Gauge Meter (DGS)
5. Connecting wire.
6. Electromagnets with adjustable pole gap.
THEORY:
A Semiconductors is a special type of material that has an intermediate conductivity between a
conductor and an insulator.
Conductivity of a semiconductor can vary under an electric field. Current can either flow due to
flow of the electrons or due to flow of the holes (positively charged) Depending upon the
majority of charge carriers, they are classified as the positive or negative I.e., p type or n type
semiconductors.
In 1897, Sir Edwin Hall discovered the effect of electric and magnetic field over a semiconductor
called the Hall Effect. This effect helps us to determine the number of charge carriers also.
Current is formed by the movement of many small charge carriers such as the holes and the
electrons. Moving charges in space experience a force called LORENTZ FORCE.
When a Magnetic field is present in the direction perpendicular to the motion of the moving
charges. The charges move along a curved path and get accumulated on of the face of the
material.
If a current carrying conductor placed in a perpendicular magnetic field, a potential difference
will generate in the conductor which is perpendicular to both magnetic field and current. This
phenomenon is called Hall Effect. In solid state physics, Hall effect is an important tool to
characterize the materials especially semiconductors. It directly determines both the sign and
density of charge carriers in a given sample.
A current is made to flow through the sample material and the voltage difference between its
top and bottom is measured. A current flow in response to an applied electric field with its
direction as conventional and it is either due to the flow of holes in the direction of current or
the movement of electrons backward.
Lorentz force, F = q (V X B) causes the carriers to curve upwards.
This charge imbalance produces an electric field which counteracts with the magnetic force and
a steady state is established.
PROCEDURE:
(These Experiments have been performed by simulation and not physically)
To measure the magnetic field generated in the solenoid
1: Select Magnetic field Vs Current from the procedure combo-box.
2: Click Insert Probe button
3: Placing the probe in between the solenoid by clicking the wooden stand in the simulator.
4: Using Current slider, varying the current through the solenoid and corresponding magnetic
field is to be noted from Gauss meter.
Hall Effect apparatus:
1: Select Hall Effect Setup from the Select the procedure combo box.
2: Click Insert Hall Probe button.
3: Placing the probe in between the solenoid by clicking the wooden stand in the simulator.
4: Set "current slider" value to minimum.
5: Select the material from “Select Material” combo-box.
6: Select the Thickness of the material using the slider Thickness.
7: Vary the Hall current using the slider Hall current.
8: Note down the corresponding Hall voltage by clicking “show voltage” button.
9: Then calculate Hall coefficient and carrier concentration of that material using the equation.
OBVERSATION AND CALCULATIONS:
PART-1
1 Tesla = 104 Gauss
CALIBRATION
CURRENT (Im)
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
MAGNETIC FIELD(TESLA)
0.1482
0.2223
0.2964
0.3706
0.4447
0.5188
0.5929
0.6670
0.7411
MAGNETIC FIELD(GAUSS)
1482
2223
2964
3706
4447
5188
5929
6670
7411
1) Im = 1A; B3 = 1482G
Hall current(mA)
Hall Voltage(mV)
2) Im = 2.5A; B2 = 3706G
Hall current(mA)
Hall Voltage(mV)
1
5.751
1
14.378
1.5
8.627
1.5
21.567
2
11.502
2
28.756
2.5
14.378
2.5
35.945
3
17.253
3
43.13
3.5
20.129
3.5
50.322
4
23.005
4
57.511
4.5
25.880
4.5
64.700
5
28.756
5
71.889
3) Im = 5A; B1 = 7411G
Hall current(mA)
Hall Voltage(mV)
1
28.756
1.5
43.133
2
57.511
2.5
71.889
3
86.267
3.5
100.645
4
115.023
4.5
129.400
5
143.778
PART-1
CALCULATIONS:
RESULTS:
1) Type of Charge Carriers = (+) Holes
2) Hall Coefficient (Rh) = 1.940 x 104 cm3/C
3) Charge Carrier Density = 3.218 x 1014/cm3
OBSERVATIONS AND CALCULATIONS:
PART-2
Ip = 1mA
CURRENT (Im)
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
MAGNETIC FIELD(GAUSS)
1482
2223
2964
3706
4447
5188
5929
6670
7411
HALL VOLTAGE (mV)
5.751
8.627
11.502
14.378
17.253
20.129
23.005
25.880
28.756
MAGNETIC FIELD(GAUSS)
1482
2223
2964
3706
4447
5188
5929
6670
7411
HALL VOLTAGE (mV)
11.502
17.253
23.005
28.756
34.507
40.258
46.009
51.760
57.511
MAGNETIC FIELD(GAUSS)
1482
2223
2964
3706
4447
5188
5929
6670
7411
HALL VOLTAGE (mV)
28.756
43.133
57.511
71.889
86.267
100.645
115.023
129.400
143.778
Ip = 2mA
CURRENT (Im)
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Ip = 5mA
CURRENT (Im)
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
PART-2
CALCULATIONS:
RESULTS:
1) Type of Charge Carriers = (+) Holes
2) Hall Coefficient (Rh) = 1.940 × 104 cm3/C
3) Charge Carrier Density = 3.218 × 1014 / cm3
PRECAUTIONS:
1) Since this was in simulation, errors in reading are not considered, but in the lab it
will/should berecorded.
2) Don’t use “ADJUST ZERO” during the experiment
3) Do not play with DC regulated power supply.
4) Do not reverse the direction of direction of (Im) during the experiment.
Name: Kartik S Hase
Roll Number: 20CHE135
Branch: FYCE
Date: 27/02/2021
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