Growth of InGaAs/AlAsSb single quantum wells with various AlAs diffusion-stopping layers

Sb surfactant mediated growth of InAs/AlAs0.56Sb0.44 strained quantum well for intersubband absorption at 1.55 μm

“…The insertion of AlAs thin layers at interfaces which limits inter-diffusion 10 and (/or) the use of InGaAs alloys with high In content 11 to increase the quantum confinement have been proposed to blue shift the ISBT. Despite these procedures, ISBT observation at 1.55 lm in single QW has been not yet reported in this material system.…”

“…A double-Ge (220)-crystal monochromator was employed. Transmission Electron Microscopy (TEM) observations were made on cross-sectional lamellas thinned in the [1][2][3][4][5][6][7][8][9][10] 200 kV on a TECNAI F-20 microscope equipped with a spherical aberration corrector, which allows to avoid the delocalization effect at interfaces and to achieve a 0.12 nm spatial resolution. PL measurements were carried out at 15 K in a closed cycle cryostat.…”

“…However, intermixing and segregation lead to a shift of ISBT to longer wavelength. 10 In order to investigate the actual profile of surfactant mediated grown InAs QW, a strain analysis was performed at a very local scale applying the Geometric Phase Analysis (GPA) to an HREM image (Figure 3(a)). The GPA method captures the variations with respect to a reference zone of the in-plane and out-of-plane lattice parameters, e xx and e yy , respectively.…”

Molecular beam epitaxy of AlAsSb/AlAs/InGaAs coupled double quantum wells with extremely thin AlAs center barrier

“…A candidate material for a well in the InGaAs/(In)AlAs/AlAsSb system is In x Ga 1Àx As with the indium content (x) greater than 0.53. If this candidate material is used as the well, strain compensation is required [7] because the In x Ga 1Àx As (x40:53) layer on InP induces compressive strain. In order to carry out strain compensation, AlAs, whose lattice constant is smaller than that of InP, is a suitable component of the center barrier layer of the CDQWs.…”

Strain compensation for InGaAs–AlAs–AlAsSb coupled double quantum wells by controlling the barrier layer composition

“…Thus far, an ultrafast absorption recovery of 690 fs and 10 dB saturation at a pumping energy of 16 pJ was attained at 1.55 mm [1,2]. In this material system, the insertion of additional thin AlAs layers between the Si-doped InGaAs wells and AlAsSb barriers is effective in preventing the exchange reaction of the As and Sb atoms from the InGaAs to AlAsSb interface [3,4]. Since the insertion of the AlAs layers, which are lattice mismatched to the InP substrate, introduces a large residual strain in the CDQWs, InGaAs wells with a high In composition of 0.8 were used in the CDQWs to compensate for this strain [2].…”