Semiconducting Devices Question 194
Question: The energy band diagrams for three semiconductor samples of silicon are as shown. We can then assert that
[Haryana CEE 1996]
Options:
A) Sample X is undoped while samples Y and Z have been doped with a third group and a fifth group impurity respectively
B) Sample X is undoped while both samples Y and Z have been doped with a fifth group impurity
C) Sample X has been doped with equal amounts of third and fifth group impurities while samples Y and Z are undoped
D) Sample X is undoped while samples Y and Z have been doped with a fifth group and a third group impurity respectively
Show Answer
Answer:
Correct Answer: D
Solution:
In sample x no impurity level seen, so it is undoped.
In sample y impurity energy level lies below the conduction bond so it is doped with fifth group impurity.
In sample z, impurity energy level lies above the valence band so it is doped with third group impurity.
