A computer solution for the transport equations and Poisson's equation has been obtained for the steady-state behaviour in a PN-junction diode. Assuming dopings of 10 18/cm 3 for acceptors and 10 15/cm 3 for donors, and using the Hall-Shockley-Read recombination process, we have been able to solve for the currents, concentrations, energy levels, and field in the P-region, N-region, and space-charge region separately. No approximations are made which are not a consequence of the relative doping levels. Our main conclusions are that ( a) the potential drop in the N-region causes the forward current to vary as exp( qV/ nkt), where n increases with current and ( b) the reverse current does not saturate because of recombination in the space-charge region.