Effects of nonradiative recombination on the temperature characteristics of threshold current density in 670 nm GaInAsP-AlGaAs visible lasers

The effect of nonradiative recombinations on the temperature characteristics of threshold in 670 nm GaInAsP lasers are investigated with theoretical calculations. Lasers with different Al contents (X/sub Al/) and p-type doping carrier concentrations of the AlGaAs cladding layers were fabricated in order to evaluate the threshold current densities (J/sub th/) and the temperature characteristics of J/sub th/. The dependence of J/sub th/ on the active layer thickness was also evaluated. By subtracting the calculated pure radiative recombination component of J/sub th/ from the experimental J/sub th/ values, the nonradiative recombination current densities were obtained as a function of inverse temperature. The thermal activation energies were evaluated for different Delta E/sub g/. It was found that the nonradiative recombinations were governed by the heterobarrier heights. The increase of J/sub th/ with decreasing X/sub Al/ was explained theoretically in terms of the carrier leakage over heterobarriers. It is concluded that the carrier leakage components are the main nonradiative recombination processes in these lasers.<
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