Electronic Devices Question 93
Question: A Ge specimen is doped with Al. The concentration of acceptor atoms is ~1021 atoms/m3. Given that the intrinsic concentration of electron hole pairs is $ \tilde{\ }10^{19}/m^{3} $ , the concentration of electrons in the specimen is
[AIIMS 2004]
Options:
A) $ 10^{17}/m^{3} $
B) $ 10^{15}/m^{3} $
C) $ 10^{4}/m^{3} $
D) $ 10^{2}/m^{3} $
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Answer:
Correct Answer: A
Solution:
$ n _{i}^{2}=n _{h}n _{e} $
Therefore $ {{(10^{19})}^{2}}=10^{21}\times n _{e} $
Therefore $ n _{e}=10^{17}/m^{3}.$