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प्रश्न
Distinguish between intrinsic and extrinsic semiconductor. (Give any two points).
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उत्तर
| Intrinsic semiconductors | Extrinsic semiconductors | |
| 1) | Semiconductor in the pure form is known as intrinsic semiconductor. |
The semiconductor, resulting from mixing of impurity in it, is known as extrinsic semiconductor |
| 2) | Their conductivity is low | Their conductivity is high. |
| 3) | Its electrical conductivity is a function of temperature alone. |
Its electrical conductivity depends upon the temperature as well as on the quantity of impurity atoms doped in the structure |
| 4) | The number of free electrons in conduction band is equal to the number of holes in valence band. |
In these semiconductors, number of free electrons and number of holes are unequal |
| 5) | These are not practically used | These are practically used |
| 6) | In these, the Fermi energy level lies in the middle of valence band and conduction band. | In these, the Fermi energy level shifts towards valence or conduction energy band. |
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संबंधित प्रश्न
Distinguish between 'intrinsic' and 'extrinsic' semiconductors
The number of silicon atoms per m3 is 5 × 1028. This is doped simultaneously with 5 × 1022 atoms per m3 of Arsenic and 5 × 1020 per m3 atoms of Indium. Calculate the number of electrons and holes. Given that ni= 1.5 × 1016 m−3. Is the material n-type or p-type?
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When p-n junction diode is forward biased, then ______.
In p-type semiconductor, the dopant is ______.
In p-type semiconductor, ______.
Distinguish between n-type and p-type semiconductors.
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The figure shows a piece of pure semiconductor S in series with a variable resistor R and a source of constant voltage V. Should the value of R be increased or decreased to keep the reading of the ammeter constant, when semiconductor S is heated? Justify your answer
Two crystals C1 and C2, made of pure silicon, are doped with arsenic and aluminium respectively.
Identify the extrinsic semiconductors so formed.
Name the extrinsic semiconductors formed when pure germanium is doped with a trivalent impurity. Draw the energy band diagram of extrinsic semiconductors so formed.
Name the extrinsic semiconductors formed when pure germanium is doped with a Pentavalent impurity. Draw the energy band diagram of extrinsic semiconductors so formed.
In an extrinsic semiconductor, the number density of holes is 4 × 1020 m-3. If the number density of intrinsic carriers is 1.2 × 1015 m-3, the number density of electrons in it is ______.
Pieces of copper and of silicon are initially at room temperature. Both are heated to temperature T. The conductivity of ______.
With an increase in the temperature, the electrical conductivity of a semiconductor ______.
What type of semiconductor is obtained when a crystal of silicon is doped with a trivalent element?
The majority charge carriers in a P-type semiconductor are ______.
