Strain relaxation and stress-driven interdiffusion in InAs∕InGaAs∕InP nanowires

Abstract

The authors have investigated strain relaxation in InAs∕InGaAs∕InP nanowires (NW’s). Transmission electron microscopy images show an additional stress field attributed to compositional modulation in the ternary layer, which disrupts NW formation and drives Ga interdiffusion into InAs, according to grazing incidence x-Ray diffraction under anomalous scattering conditions. The strain profile along the NW, however, is not significantly affected when interdiffusion is considered. Results show that the InAs NW energetic stability is preserved with the introduction of ternary buffer layer in the structure.

Effect of annealing on the compositional modulation of InAlAsSb

“…In order to achieve lattice matching, the In and As compositions in the quaternary layer is within the range of 0.15 < x < 0.20 and 0.69 < y < 0.73. The samples were grown in an As-Sb molecular beam epitaxy (MBE) system at a substrate temperature of 450 • C. After the growth the samples were transferred to a metal organic chemical vapour deposition (MOCVD) 7 system where they were annealed under As overpressure. Table 1 shows the layering of the studied samples and the conditions of the postannealed treatments.…”

“…5 It is well-known that composition modulation in III-V semiconductor broadens photoluminescence curves reducing their efficiency [6]. Furthermore, the thickness and composition of the buffer also affects to the compositional modulation [7]. So, the knowledge of growth conditions that cause compositional fluctuations is essential to optimize the performance of these optoelectronic devices [6,[8][9][10].…”

Shorter wavelength emission with InAs quantum dots growth directly on large bandgap quaternary (In0.68Ga0.32As0.7P0.3) barriers for high current injection efficiency

“…Therefore, we suppose the composition of the dots may include gallium and phosphorus. We used our computational tool to estimate the gallium diffusion [20,21] and the As/P partial exchange during growth [20,22,23] that might have caused the change in composition. Fig.…”

Shape control of InGaAs nanostructures on nominal GaAs(001): dashes and dots

“…Different strain relaxation mechanisms have been reported, including anisotropic relaxation [3,6] for InAs/InP systems and isotropic relaxation for InGaAs [7] on GaAs(001) substrates, as possible explanations for QWrs and QDs, respectively. In addition, InAs QWrs [8][9][10] and QDhs [11] were observed on InGaAs, InAlAs and InAlGaAs alloys that were grown, lattice matched, on InP(001) substrates. 1 Author to whom any correspondence should be addressed.…”

“…The epilayers were subsequently annealed at higher temperatures. Low temperature growth has several advantages over conventional SK growth, such as suppression of indium segregation [13] and desorption [14], composition modulation due to segregation [10], and intermixing [15]. In particular, it has been reported [16] that indium segregates over a wide temperature range, from 370 to 520 • C, which overlaps with the SK growth window because the conventional SK growth mode typically requires the GaAs substrate to be above 400 • C so the adatoms can diffuse into lower energy sites to form islands.…”