Single strained, medium‐doped (5×1018/cm3) GaAs photocathodes show the surface charge limit (SCL). The SCL poses a serious problem for operation of polarized electron sources at future linear colliders such as the NLC/JLC. A high‐gradient‐doping technique has been applied to address this problem. A 5 –7.5 nmp‐type surface layer doped to 5×1019/cm3is found sufficient to overcome the SCL, while maintaining high beam polarization. This technique can be employed to meet the charge requirements of the NLC with a polarization approaching 80&percent;. © 2003 American Institute of Physics