LABORATORY WORK #6
PHOTOCONDUCTIVITY PROPERTIES
OF SEMICONDUCTORS
PhysicVirtualLab Software Package
Procedure:
Task 1
3.1.1 Take dark current-voltage characteristic by turning in K1, i.e. dependence of dark current of photoresistor (from amperemeter) on voltage.
Task 2 |
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3.2.1 Turn on source of light by closing K2. |
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3.2.2 Take current-voltage characteristic |
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( ) at constant illumination |
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(E=const). Measure current |
of |
lightened photoresistor |
using the |
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milliamperemeter at every constant distance l from the source of light |
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until photoresistor (at constant E), by changing U (use potentiometer). |
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Fill table 1 with your results. Since Id is negligible |
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Table 1 |
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U, V |
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l1 |
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I1, mA |
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Ф1=E1S |
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l2 |
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I2 |
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Ф2=E2S |
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l3 |
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I3 |
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Ф3=E3S |
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l4 |
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I4 |
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Ф4=E4S |
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3.2.3 Illumination can be calculated by |
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, where J is light force, 1is |
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distance from light source until photoresistor (in meter).
3.2.4Plot current-voltage characteristics.
3.2.5Fill Table 2 using data from Table 1 and use it to plot optical
characteristics at |
( ) at |
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PhysicVirtualLabs Project Team, IITU
Copyright 2014
LABORATORY WORK #6
PHOTOCONDUCTIVITY PROPERTIES
OF SEMICONDUCTORS
PhysicVirtualLab Software Package
Table 2
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Ф1 |
Ф2 |
Ф3 |
Ф4 |
U1 |
I |
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U2 |
I |
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U3 |
I |
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U4 |
I |
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3.2.6Determine sensitivity K from current-voltage characteristics by formula
(6)for different light flux and voltage U. Light flux is calculated by
,where S=35 mm2.
3.2.7Analyze your results and draw conclusion.
Task 3
3.3.1To take spectral characteristics click on “next task” and turn on K2. At =3 cm switch wavelength of of light radiation from 0.20 μm until 0.85
μm with step 0.05 μm and write data from amperemeter. Plot graph for
I = f(λ).
3.3.2Analyze your results and draw conclusion.
4.QUESTIONS
4.1 Energy band theory for conductor, semiconductor and dielectric.
4.2 Pure semiconductor and semiconductor with impurity.
4.3 Inner photoeffect.
4.4 Explain photoconductivity.
4.5 Photoresistance, application of photoresistance.
PhysicVirtualLabs Project Team, IITU
Copyright 2014
LABORATORY WORK #6
PHOTOCONDUCTIVITY PROPERTIES
OF SEMICONDUCTORS
PhysicVirtualLab Software Package
5.REFERENCES:
5.1S.M. Ryvkin. Photoelectric phenomena in semiconductors. Physmatgiz. 1963.
5.2V.L. Bonch-Bruevich, S.G. Kalashnikov. Physics of semiconductors. –
M.: «Nauka». 1990.
5.3T.I. Trofimova «General physics» Moscow, Vyschaya schkola, 2001.
5.4I.V. Savelyev. «Course of general physics». V.3, M.: «Nauka». 1977.
PhysicVirtualLabs Project Team, IITU
Copyright 2014