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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
In a p-type semiconductos, which of the following statement is true:
In a p-type semiconductor, the acceptor impurity produces an energy level ______
Electronic configuration of germanium is 2, 8, 18 and 4. To make it extrinsic semiconductor small quantity of antimony is added. The correct statement is ____________.
Semiconductors formed by doping germanium (Ge) with aluminium (Z = 13) and antimony (Z = 51) are ______.
In n-type semiconductor, the fifth electron ______.
In n-type semiconductor majority carriers and minority carriers are respectively ______.
In p-type semiconductor, the dopant is ______.
In p-type semiconductor, ______.
The electron and hole concentration in a semiconductor in thermal equilibrium is given by ______.
Distinguish between n-type and p-type semiconductors.
In a pure semiconductor crystal of Si, if antimony is added then what type of extrinsic semiconductor is obtained. Draw the energy band diagram of this extrinsic semiconductor so formed.
The conductivity of a semiconductor increases with increase in temperature because ______.
Why are elemental dopants for Silicon or Germanium usually chosen from group XIII or group XV?
Sn, C, and Si, Ge are all group XIV elements. Yet, Sn is a conductor, C is an insulator while Si and Ge are semiconductors. Why?
Suppose a ‘n’-type wafer is created by doping Si crystal having 5 × 1028 atoms/m3 with 1 ppm concentration of As. On the surface 200 ppm Boron is added to create ‘P’ region in this wafer. Considering n i = 1.5 × 1016 m–3, (i) Calculate the densities of the charge carriers in the n and p regions. (ii) Comment which charge carriers would contribute largely for the reverse saturation current when diode is reverse biased.
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.
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 ______.
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 ______.
