Single quantum dot emission at telecom wavelengths from metamorphic InAs/InGaAs nanostructures grown on GaAs substrates

Abstract

We report on the growth by molecular beam epitaxy and the study by atomic force microscopy and photoluminescence of low density metamorphic InAs/InGaAs quantum dots. subcritical InAs coverages allow to obtain 10 8 cm −2 dot density and metamorphic In x Ga 1−x As ͑x = 0.15, 0.30͒ confining layers result in emission wavelengths at 1.3 m. We discuss optimal growth parameters and demonstrate single quantum dot emission up to 1350 nm at low temperatures, by distinguishing the main exciton complexes in these nanostructures. Reported results indicate that metamorphic quantum dots could be valuable candidates as single photon sources for long wavelength telecom windows.

Time resolved emission at 1.3 μm of a single InAs quantum dot by using a tunable fibre Bragg grating

“…The µ-PL linewidth was considerably reduced (∼ 250 µeV) compared to previous samples (1 meV in reference [7]). …”

“…Single QD emission in the long wavelength range in these structures has been demonstrated by us in reference [7]. The use of metamorphic InGaAs layer allows for the red-shift of the emission wavelength, thanks to the reduction of strain of QDs and band discontinuities [17], while the deposition of a subcritical coverage of InAs followed by annealing allows to obtain very low QD density (1 x 10 8 cm -2 ) for structures grown on metamorphic layers [18].…”

“…The use of metamorphic InGaAs layer allows for the red-shift of the emission wavelength, thanks to the reduction of strain of QDs and band discontinuities [17], while the deposition of a subcritical coverage of InAs followed by annealing allows to obtain very low QD density (1 x 10 8 cm -2 ) for structures grown on metamorphic layers [18]. and XX 0 transitions, and the larger value for X + with respect to X 0 can be justified by a random carrier capture mechanism, as previously demonstrated for InAs single QDs emitting at 900-1000 nm [19], [7] In this way, continuous lines at the inset of figure 1.c represent the best fit to the measured integrated intensity variation by using a random population model [19]. The good agreement demonstrates the validity of the above given excitonic assignation, except for the case of XX 0 intensity at high excitation powers, because we only considered S levels for the QD.…”

Exciton and multiexciton optical properties of single InAs/GaAs site-controlled quantum dots

“…The neutral exciton presents the smallest slope, m(X 0 ) ¼ 0.7, while the slope of the biexciton is a factor two larger, m(XX 0 ) ¼ 1.38. 27,28 The identification of XX 0 does not present any doubt, because in addition its decay time is half of that measured for the exciton-like species [ Fig. 2(b)].…”

Silver Embedded Nanomesas as Enhanced Single Quantum Dot Emitters in the Telecommunication C Band

“…[3][4][5][6][7][8] Extremely low density InAs or InAs/InGaAs QDs on GaAs substrates were reported at wavelengths up to 1.4 μm, which is the limit on these substrates. [9][10][11] InAs QDs grown on InP substrates, however, allow the growth of QDs with substantially longer emission wavelengths; tunable wavelength was reported between 1.3 and 1.7 μm. [12][13][14] Several compounds were used as buffer layers to investigate the growth of InAs QDs (or other nanostructures) on InP substrates, such as InP, 15) InAlAs, 16) InGaAs, 17) InGaAsP, 18) and InGaAlAs.…”