Exciton recombination dynamics inInAs∕InPself-assembled quantum wires

Abstract

In this work we investigate the exciton recombination dynamics in InAs/ InP semiconductor self-assembled quantum wires, by means of continuous wave and time resolved photoluminescence. The continuous wave photoluminescence results seem to indicate that the temperature quenching of the emission band seems to be more probably due to unipolar thermal escape of electrons towards the InP barrier. On the other hand, the analysis of time resolved photoluminescence reveals that the temperature dependence of the radiative and nonradiative recombination times is mainly determined by the dynamics of excitons localized by disorder ͑high energy tail of the PL band͒ and strongly localized ͑low energy tail of the PL band͒ in local size fluctuations of the quantum wires.

Localization effects on recombination dynamics in InAs/InP self-assembled quantum wires emitting at 1.5 μm

“…As a result, the time resolved measurements were obtained as mono-exponential transients instead of the more complex decays reported for the high power regime. 4,15 For instance, in Figure 3(a), a typical PL transient is shown for QWRs of family P1 (0.827 eV) at 12 K. The decay of the optical signal is accompanied by the system response for the laser excitation. As shown in the figure, a mono-exponential decay function (red continuous line) is used to fit the experimental curve after convolution with the system response, in shadow.…”

Purcell effect in photonic crystal microcavities embedding InAs/InP quantum wires

“…The fundamental optical modes of Ln defect PCMs (linear cavities formed by eliminating "n holes" from the photonic lattice) are characterized by a large linear polarization anisotropy, which is maximum along the direction perpendicular to the linear defect, as was experimentally demonstrated for the L7-cavity [15]. QWRs present a linear polarization anisotropy which is maximum along the QWR axis ( [1][2][3][4][5][6][7][8]13,14] crystalline direction) [10]. To study the effect of polarization, two sets of L7-cavities have been fabricated and aligned either parallel or perpendicular to the QWRs.…”

“…The growth is made by molecular beam epitaxy (MBE). InAs QWRs are aligned along the [1][2][3][4][5][6][7][8]13,14] direction forming a quasi-periodic array. The average height and width are 3.2 and 10.3 nm respectively, as determined from transmission electron microscopy (TEM) studies carried out in samples with buried QWRs grown in the same way than those studied in this work [16].…”

“…In spite of their peculiar properties, the QWRs are still less studied than other kind of nano-structures, and few works about the Purcell effect on QWRs embedded in PCMs have been reported up to date. Among them, Atlasov et al demonstrated the integration of site-controlled InGaAs/GaAs V-groove QWRs into a PCM where the coupling of the quantum emitter and the cavity modes exhibit a SE enhancement by a factor 2.5 [13,14]. In this work we present a systematic study of linear PCMs with self-assembled InAs/InP QWRs embedded together with a detailed model to simulate the Purcell effect in such system.…”

In As ∕ In P single quantum wire formation and emission at 1.5μm

“…[6][7][8][9][10] Depending on the wire size and composition, emission tuning capability in the 1.2-1.9 m range has been demonstrated, and both continous wave and time-resolved optical characterizations have been performed on high density QWR arrays. [11][12][13][14] In such situation, long wavelength emission from single QWRs would be desirable. However, for the time being, single quantum wire optical spectroscopy has been restricted mainly to GaAs/ AlGaAs nanostructures emitting on the visible range.…”