Advertisements
Advertisements
Question
Name the extrinsic semiconductors formed when pure germanium is doped with a Pentavalent impurity. Draw the energy band diagram of extrinsic semiconductors so formed.
Solution
When a pure Germanium is doped with a pentavalent impurity, n-type extrinsic semiconductor is formed.
APPEARS IN
RELATED QUESTIONS
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?
Distinguish between intrinsic and extrinsic semiconductor. (Give any two points).
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 ____________.
In n-type semiconductor, the fifth electron ______.
In p-type semiconductor, ______.
The electron and hole concentration in a semiconductor in thermal equilibrium is given by ______.
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.
What type of semiconductor is obtained when a crystal of silicon is doped with a trivalent element?
