Chapter 5, Problem 5.25P

Electron and hole concentration increase with temperature. For pure silicon, suitable expression are p_h=6200T^1.5e^-7000/TC/m³. The functional dependence of the motilities on temperature is given by ${\mu }_h=2.3\times {10}^5{T}^{-2.7}{m}^2/V.s$ and ${\mu }_e=2.1\times {10}^5{T}^{-2.5}{m}^2/V.s,$

where the temperature, T, is in degrees Kelvin. Find σ at: (a) 0°C; (b) 40°C; (c) 80°C.