An inhomogeneously doped Si sample is at thermal and electrical equilibrium. By some nonequilibrium measurements at T = 290.14K, it was determined that this Si sample contains an equilibrium internal electric field of 10,000V/cm across a thin layer of 1.0μm thick inside the sample.
What are the electron and hole concentration ratios on the two surfaces of the thin layer, N1/N2 and P1/P2, to account for this built-in electric field. Use kT/q = 0.0250V at T = 290.14K.