Measurement of radiative and nonradiative recombination rates in InGaAsP and AlGaAs light sources

A small signal method is used to measure the carrier lifetime as a function of injected carrier density, and the results are used to determine the radiative and nonradiative recombination rates for AlGaAs LED\´s and 1.3 μm InGaAsP lasers. For AlGaAs LED\´s the radiative recombination constant decreases with injected carrier density and the rate equation contains a small nonradiative Cn³term. The low internal efficiency of 1.3 μm InGaAsP lasers is found to be primarily caused by two factors: a radiative coefficient which strongly decreases with the injected carrier density, and CHHS Auger recombination having a recombination coefficient of cm⁶/s. A recombination term representing carrier leakage is observed in some devices, but it is not the principal cause of low internal efficiency.