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प्रश्न
Why are elemental dopants for Silicon or Germanium usually chosen from group XIII or group XV?
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उत्तर
The size of dopant atoms should be such as not to distort the pure semiconductor lattice structure and yet easily contribute a charge carrier on forming covalent bonds with Si or Ge.
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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?
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 ____________.
A donor impurity results in ______.
In n-type semiconductor majority carriers and minority carriers are respectively ______.
In p-type semiconductor, the dopant is ______.
In p-type semiconductor, ______.
State how a p-type semiconductor will be obtained from a pure crystal of a semiconductor.
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 ______.
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 ______.
Pieces of copper and of silicon are initially at room temperature. Both are heated to temperature T. The conductivity of ______.
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 ______.
