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The number density of electron is a semiconductor is 8xx10^(13) cm^(-3) and number density of hole is 5xx10^(12) cm^(-3) then, (1) Which type of this semiconductor is? (2) How much is resistivity of it?(Mobility of electron is 23000 cm^(2)V^(-1)s^(-1) and mobility of hole is 100 cm^(2)V^(-1)s^(-1) and e=1.6xx10^(-19)C) |
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Answer» `p-29.45xx10^(-2)Omegam` `n_(e )=8xx10^(13)cm^(-3)=8xx10^(19)m^(-3)` `n_(h)=5xx10^(12) cm^(-3)=5xx10^(18)m^(-3)` `mu_(e )=23000 cm^(2)V^(-1)s^(1)=2.3m^(2)V^(-1)s^(-1)` `mu_(h)=100cm^(2)V^(-1)s^(-1)=0.01m^(2)V^(-1)s^(-1)` Here, the number of ELECTRONS is HIGHER than the holes so semiconductor will be n-type semiconductor `(n_(e ) gt n_(h))` `sigma=(1)/(rho)=e(mu_(e )mu_(e )+n_(h)mu_(h))=1.6xx10^(-19)` `[8xx10^(19)xx2.3xx5xx10^(18)xx0.01]` `=1.6xx10^(-19)[1.84xx10^(20)+5xx10^(16)]` `(1)/(rho) ~~29.45"mho m"^(-1)` `therefore rho=(1)/(29.45)=3.396xx10^(-2)`ohm m `therefore rho=3.396xx10^(-2)Omegam` |
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