Carrier recombination processes in MOVPE and MBE grown 1.3 μm GaInNAs edge emitting lasers

By measuring the spontaneous emission (SE) from metal organic vapour phase epitaxy (MOVPE) grown ∼1.3 μm GaInNAs/GaAs-based lasers during normal operation, we have quantitatively determined the variation of each of the current paths present in the devices as a function of temperature from 130 to 370 K and compared these with results previously obtained for molecular beam epitaxy (MBE) grown GaInNAs lasers. From the SE measurements we determine how the current, I, close to threshold, varies as a function of carrier density, n, which enables us to separate out the main current paths corresponding to monomolecular (defect-related), radiative or Auger recombination respectively. We find that at room temperature (RT), defect-related recombination contributes ∼360 A/cm2 (MBE) and ∼565 A/cm2 (MOVPE) to the total current density at threshold. Radiative recombination accounts for ∼110 A/cm2 (MBE) and 195 A/cm2 (MOVPE) of Jth with the remaining ∼180 A/cm2 (MBE) and 760 A/cm2 (MOVPE) are due to non-radiative Auger recombination. Our results suggest that a larger threshold carrier density in the MOVPE grown device in comparison to the MBE lasers, can reasonably explain the larger current densities of the different recombination processes at RT. We tentatively associate this with higher optical loss processes in the MOVPE grown material.