The electron concentration in silicon at T = 300 K is given by n(x) = 10^16exp(-x/18) cm^-3
where x is measured in μm and is limited to 0 ≤ x ≤ 25 μm. The electron diffusion coefficient is Dn = 25 cm2/s and the electron mobility is μn = 960 cm2/V-s. The total electron current density through the semiconductor is constant and equal to Jn = -40 A/cm2. The electron current has both diffusion and drift current components. Determine the electric field as a function of x which must exist in the semiconductor.