Recombination and loss mechanisms in low-threshold InAs-GaAs 1.3-/spl mu/m quantum-dot lasers

Abstract

We show that even in quantum-dot (QD) lasers with very low threshold current densities (J th = 40-50 A/cm 2 at 300 K), the temperature sensitivity of the threshold current arises from nonradiative recombination that comprises ∼60% to 70% of J th at 300 K, whereas the radiative part of J th is almost temperature insensitive. The influence of the nonradiative recombination mechanism decreases with increasing hydrostatic pressure and increasing band gap, which leads to a decrease of the threshold current. We also studied, for the first time, the band gap dependence of the radiative part of J th , which in contrast increases strongly with increasing band gap. These results suggest that Auger recombination is an important intrinsic recombination mechanism for 1.3-µm lasers, even in a very low threshold QD device, and that it is responsible for the temperature sensitivity of the threshold current.

Modeling the temperature characteristics of InAs/GaAs quantum dot lasers

“…Finally, a dominant role of Auger NR recombination at RT has been suggested by the dependence of threshold current as a function of applied pressure 18 and by the nonlinear light-current characteristics. 19 This last explanation is particularly appealing, as Auger processes are known to determine the temperature dependence of InP-based 1.3-1.55 m QW lasers.…”

Influence of de-tuning and non-radiative recombination on the temperature dependence of 1.3 μm GaAsSb/GaAs vertical cavity surface emitting lasers

“…Explanations include non-radiative processes such as Auger recombination, gain saturation, or carrier excitation. 6 Quantum dot VCSELs at 1.28 lm have all recently been demonstrated. 7 1.3 lm GaInNAs(Sb)-based QW VCSELs have been produced at 1.53 lm under pulsed excitation, 8 however, the material quality of dilute nitrides remains an issue.…”

The influence of growth conditions on carrier recombination mechanisms in 1.3 μm GaAsSb/GaAs quantum well lasers

“…1 Moreover, due to the lack of lattice matching and high refractive index contrast materials to form all-epitaxial distributed Bragg reflectors (DBRs), it is also very difficult to fabricate monolithic vertical cavity surface emitting lasers (VCSELs) in the InP material system. 2 The GaAs-based 1.3 lm GaInNAs QWs 3,4 and 1.3 lm InAs/GaAs quantum dots 5,6 have also been investigated extensively. The performance of such lasers is still far from ideal.…”