Question

A semiconductor is known to have an electron concentration of $8\times {10}^{13}/{cm}^3$ and hole concentration of $5\times {10}^{12}/{cm}^3$. The semiconductor is.

• A. N- type
• B. P-type
• C. intrinsic
• D. insulator

Answer 1

The correct option is A N- type

Given:

$n_e=8\times {10}^{13}/c{m}^3$ , $n_h=5\times {10}^{12}/c{m}^3$

${\mu }_e=25000c{m}^2{V}^{-1}se{c}^{-1}$

${\mu }_h=100c{m}^2{V}^{-1}se{c}^{-1}$

$\sigma =n_e{\mu }_{e}e+n_h{\mu }_{e}e$

$=(8\times {10}^{13}\times 25000+5\times {10}^{12}\times 100)\times 1.6\times {10}^{-19}$

$=320\times {10}^{-3}mmho/cm$

$\therefore$ $n_e>n_h(N-type)$

R