Two distinct processes are suggested for the formation ofp‐njunctions in crystal platelets of GaP grown from Ga solution doped with Zn, Te, and O, over wide ranges of composition and growth conditions. In each growth melt, about one half of thep‐type crystals contain a shallown‐type surface layer, ∼2 &mgr; in thickness, formed by out‐diffusion of Zn after growth. Thesep‐njunctions have relatively high (>10−3) external electroluminescence quantum efficiencies at room temperature. The remainingp‐type crystals contain deeper, less efficient junctions, built into the crystals by impurity segregation effects during growth. The efficiencies ofp‐njunctions degrade with the heat treatment at 600°C used to alloy the Ohmic contacts. The extent of degradation correlates with the dislocation density and is ascribed to precipitation. The precipitates nucleate preferentially in the junction plane and grow with subsequent heat treatment.