In this paper, an analytical model is developed to optimize the charge profile in an IGBT for the trade-off between the on-state performance and turn-off losses. It is found that, in contrast to a typical IGBT design, the optimum carrier distribution has a significantly higher carrier concentration at the cathode end of the device than that at the anode end. The results, which are supported by 2-D numerical simulations and experiments, provide an interesting guideline for optimizing the IGBT. Practical considerations of the predicted optimum design are discussed.