Advertisements
Advertisements
Question
Why are elemental dopants for Silicon or Germanium usually chosen from group XIII or group XV?
Advertisements
Solution
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.
APPEARS IN
RELATED QUESTIONS
Distinguish between intrinsic and extrinsic semiconductor. (Give any two points).
In a p-type semiconductor, the acceptor impurity produces an energy level ______
A donor impurity results in ______.
Semiconductors formed by doping germanium (Ge) with aluminium (Z = 13) and antimony (Z = 51) are ______.
In n-type semiconductor majority carriers and minority carriers are respectively ______.
The electron and hole concentration in a semiconductor in thermal equilibrium is given by ______.
Explain the following term:
Extrinsic 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 ______.
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?
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.
- Statement I: By doping silicon semiconductor with pentavalent material, the electrons density increases.
- Statement II: The n-type semiconductor has net negative charge. In the light of the above statements, choose the most appropriate answer from the options given below:
Pieces of copper and of silicon are initially at room temperature. Both are heated to temperature T. The conductivity of ______.
The majority charge carriers in a P-type semiconductor are ______.
