Structural and photoluminescence studies of InAsN quantum dots grown on GaAs by MBE

The effect of nitridation on the optical properties of InAs quantum dots grown on GaAs substrate by MBE

“…In fact, according to the PL results as described above, the model which can be considered for our nitrided QDs is that a thin lnAsN layer [21] covers the InAs QDs. A similar conclusion was also reported by V. Sallet et al [11] attributed the low energy shoulder in nitrided InAs QDs to the reduction of quantum confinement.…”

“…So, to eliminate the undesirable effect of the surface on device properties, the technique called 'nitridation' is being vigorously developed. In fact, the surface nitridation technology of III-V semi-conductors [8-10] has been a critical way for to extend the emitting wavelength [11,12]. Yang Zhao et al showed a significant improvement of the crystalline qualities and surface morphologies and enhancement of the electrical and optical properties for InN films after nitridation [13].…”

Complicated effects of nitrogen on the structural and optical properties of InAs(N)/GaAs quantum dots

“…Although the AFM and XRD results support the increasing trend of N incorporation into the QD as [N] increases, the actual N concentration in the coherent QD may be far smaller than [N]. This is because the N incorporation was realized not through direct exposure to the N source but through weak N leakage, and also because much of the leaked N has been incorporated into the large relaxed and defective dots [6] . The large relaxed dots at large [N] become denser, as can be observed in the AFM image and be verified by the reduced PL intensity because these large dots act as nonradiative recombination centers [1] .…”

InAs(Sb) quantum dots grown on GaAs by MBE

“…Several ways have been proposed to increase the emitted wavelength of InAs QDs, such as capping the dots with GaInAsN [1] or using a dot material having a smaller bandgap energy than InAs, like ternary InAs 1-x N x or InAs 1-x Sb x alloys. The use of diluted nitrides has revealed strong difficulties to introduce nitrogen into the dots without drastically degrading the optical quality [2]. It has also been shown that the incorporation of N is much less effective in InAs than in GaAs grown by molecular beam epitaxy (MBE) [3].…”