The time decay of the green emission, centered at 0.555 μ (2.23 eV) at 300°K, from Si–Zn-doped GaP p-n junctions was measured for temperatures in the range 100°–300°K and for current densities in the range 15–60 A/cm2. At T=102°K the green emission decayed like t−1 for long times indicating that the emission is due to pair recombination between electrons and holes bound to distant impurities. For 155°K≤ T≤300°K, the green emission decayed exponentially with a single exponential time constant which was independent of the current density and which decreased with increasing temperature as exp (−eφ/kT) with φ=0.005 eV. This exponential time decay shows that the green emission is no longer due to pair recombination; this emission is attributed to the decay of a bound exciton. The dependence of the emission intensity upon current density was found to be Jm where m=1.5 at T=300°K and decreased to 0.9 at T=102°K.