Problem: Pure silicon contains approximately 1.0x 1016 free electrons per cubic meter.(a) Referring to the table above, calculate the mean free time ? for silicon at room temperature.(b) Your answer in part (a) is much greater than the mean free time for copper. Why, then, does pure silicon have such a high resistivity compared to copper?

FREE Expert Solution

The mean free time:

$\overline{){{\mathbf{T}}}_{{\mathbf{\lambda }}}{\mathbf{=}}\frac{\mathbf{m}}{\mathbf{n}{\mathbf{e}}^{\mathbf{2}}\mathbf{\rho }}}$

(a)

For silicon, m = 9.1 × 10-31, n = 1.0 × 1016 electrons/m3, e = 1.6 × 10-19C and ρ = 2300Ω•m.

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Problem Details

Pure silicon contains approximately 1.0x 1016 free electrons per cubic meter.

(a) Referring to the table above, calculate the mean free time ? for silicon at room temperature.

(b) Your answer in part (a) is much greater than the mean free time for copper. Why, then, does pure silicon have such a high resistivity compared to copper?