Photoluminescence and scanning‐electron‐microscope measurements of minority‐carrier lifetime and luminescence efficiency have been made on Zn, N‐doped and Te, N‐doped GaP liquid‐phase‐epitaxy layers. Nitrogen concentrations are held constant at 1 × 1019cm−3, while the majority‐carrier concentrations were varied between 5 × 1016and 5 × 1018cm−3. It is shown that, for excitation levels equivalent to 10 A/cm2diode diffusion current density, a maximum external luminescence efficiency (in air) of 0.3&percent; is measured for ∼1018‐cm−3Zn, N‐doped GaP, in contrast to a maximum efficiency of 0.06&percent; for ∼1017‐cm−3Te, N‐doped GaP. These results suggest that significantly higher electroluminescent efficiencies approaching 0.3&percent; are available for diodes at 10 A/cm2, by increasing injection into ∼1018‐cm−3Zn, N‐doped GaP.