Silicon sample is 2.5 cm long and has a cross-sectional area of 0.1cm^2 . the silicon has an impurity concentration of nd=2×10^15 cm^-3 and na=0.
(a) calculate the thermal-equilibrium values of electron and hole concentrations
(b) calculate the conductivity and electron mobility if the resistance of the sample is measured to be 70 ω.
(c) if 2v bias is applied alone the length. calculate the drift current and current density.

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