Radiance saturation in small-area GaInAsP/InP and GaAlAs/GaAs LED's

The radiance/current relationship for small-area surface emitting LED's has been found to saturate at high current densities between 30 and 1000 kA/cm²in the various GaAlAs and GaInAsP devices investigated. An important saturation mechanism is found to be due to superluminescence in the plane of the active layer. Auger recombination and carrier leakage from the active region are generally of secondary importance in causing the saturation.