Postgrowth band gap trimming of InAs∕InAlGaAs quantum-dash laser

Abstract

The authors demonstrate the selective postgrowth band gap engineering and the fabrication of band gap tuned laser in InAs–InAlGaAs quantum-dash lasers grown on InP substrate. The process utilizes nitrogen implantation to induce local defects and to enhance the group-III intermixing rate spatially upon the thermal annealing. Compared with the as-grown laser, intermixed laser with wavelength shifted by 127nm shows a 36% reduction in threshold current density and produces a comparable slope of efficiency. The integrity of the intermixed material is retained suggesting that intermixing process paves way to planar, monolithic integration of quantum-dash-based devices.

Self-assembled InAs/InP quantum dots and quantum dashes: Material structures and devices

“…A spatial control of group-III intermixing rate by IID technique employing nitrogen ions (NIID) was also reported on four stacks InAs/InGaAlAs DWELL structure separated by 30 nm tensile strained InGaAlAs barrier layer [218], and plotted in Fig. 31(d).…”

Characterization of quantum dot lasers with post-growth thermal annealing

“…Amongst those numerous studies of intermixing effects, there are few studies to investigate the intermixing effects on the QD laser device [61], [62]. This opens the research gaps for us to answer the question of how the post-growth annealing process affects the device properties of the QD lasers, which is also the motivation of this research work.…”

Small signal modulation characteristics of quantum dot lasers and the effect of annealing and doping

“…Generally, the blueshift of the emission wavelength will be larger and the structural changes to the dots will be more significant with a higher annealing temperature and a longer annealing time [33]. Subsequently, the as-grown, 600 °C, and 650 °C annealed As shown in Fig.…”

“…On the contrary, reported results at the device level are significantly less. Furthermore, the existing works mainly report the static characteristics of annealed QDs [32,33,94]. To the best of our knowledge, no works have been published about the investigation of the dynamic characteristics (i.e.…”

“…the annealed samples showed a lower I th than the as-grown samples. This lower I th could be attributed to the removal of grown-in defects upon annealing since these defects act as non-radiative recombination centres in the QDs [32,33,94].…”