A model is presented to investigate the variation of majority carrier density as a function of position for a forward‐biased high—low junction. The model is developed in order to obtain a new approximate analytical solution of Poisson's equation for such a junction with a sufficiently large doping difference between the two sides. A comparison of the present work with that of previous work is made through graphical analysis. Copyright © 1993 WILEY‐VCH Verlag GmbH & Co. KGaA