Question
Question: A perfect crystal of silicon (Fig). is doped with some elements as given in the options. Which of th...
A perfect crystal of silicon (Fig). is doped with some elements as given in the options. Which of these options show n-type semiconductors?
A
B
C
D
Answer
Explanation
Solution
When silcon is doped with some group-15 element, the some of the positions in the lattice are substituted by atoms fo groups -15 elements have five valence electrons. After forming the four covalent bonds with silicon (or anyother group-14 element such as germanium). one excess electron is left on them.
Since this electron is not involed in bonding it becomes delocalized and contributre to electrical
conduction. Silicon dped with group 15 element behaves as a n-type semconductor.
