Formation of linear InAs quantum dot arrays on InGaAsP∕InP (100) by self-organized anisotropic strain engineering and their optical properties

Abstract

Wavelength controlled multilayer-stacked linear InAs quantum dot arrays on InGaAsP/InP (100) by selforganized anisotropic strain engineering: A self-ordered quantum dot crystal Appl. Phys. Lett. 93, 131906 (2008); 10.1063/1.2993178 Complex quantum dot arrays formed by combination of self-organized anisotropic strain engineering and step engineering on shallow patterned substrates J. Appl. Phys. 97, 014304 (2005); 10.1063/1.1823578Direct imaging of self-organized anisotropic strain engineering for improved one-dimensional ordering of (In,Ga)As quantum dot arrays J. Appl. Phys. 95, 109 (2004); 10.1063/1.1631069Formation of InAs quantum dot arrays on GaAs (100) by self-organized anisotropic strain engineering of a (In,Ga)As superlattice templateThe formation of linear InAs quantum dot ͑QD͒ arrays based on self-organized anisotropic strain engineering of an InGaAsP / InP ͑100͒ superlattice ͑SL͒ template in chemical beam epitaxy is demonstrated, and the optimized growth window is determined. InAs QD formation, thin InGaAsP capping, annealing, InGaAsP overgrowth, and stacking in SL template formation produce wirelike InAs structures along ͓001͔ due to anisotropic surface migration and lateral and vertical strain correlations. InAs QD ordering is governed by the corresponding lateral strain field modulation on the SL template surface. Careful optimization of InGaAsP cap layer thickness, annealing temperature, InAs amount and growth rate, and number of SL periods results in straight and well-separated InAs QD arrays. The InAs QD arrays exhibit excellent photoluminescence ͑PL͒ emission up to room temperature which is tuned into the 1.55 m telecommunications wavelength region through the insertion of ultrathin GaAs interlayers. Temperature dependent PL measurements and the linear polarization behavior indicate lateral electronic coupling of the QDs in the arrays.

Phonon-assisted radiative recombination of excitons confined in strongly anisotropic nanostructures

“…Semiconductor quantum dashes (QDashes) are selfassembled nanostructures similar to quantum dots (QDs), however strongly elongated in one of the in-plane directions [1][2][3][4][5][6][7][8]. The majority of the reports regarding such strongly asymmetric objects concern the InAs-InP (001) material system, where elongation can easily be achieved spontaneously during the growth by molecular beam epitaxy [2][3][4][5].…”

Formation of stacked linear InAs quantum dot arrays on InGaAsP/InP(100) by self‐organized anisotropic strain engineering

“…To overcome these problems, we have introduced a new concept to create linear InGaAs QD arrays of high perfection by self-organized anisotropic strain engineering in molecular-beam epitaxy (MBE) on GaAs(100) substrates [7,8] and in chemical beam epitaxy (CBE) on InP(100) substrates [9]. Formation of the latter we recall here before discussing vertical stacking of these QD arrays.…”

“…The presence of linear QD arrays depends on the substrate miscut to rotate the preferential direction of adatom surface migration away from [0 11] [9]. The optimum substrate miscut is 2° toward (110) for which straight and well-separated QD arrays are obtained by optimizing the InGaAsP cap layer thickness, annealing temperature, InAs amount and growth rate, and number of SL periods.…”

Wavelength controlled multilayer-stacked linear InAs quantum dot arrays on InGaAsP/InP (100) by self-organized anisotropic strain engineering: A self-ordered quantum dot crystal

“…This self-organization process has been proven to produce ordered QD arrays with excellent optical properties up to room temperature ͑RT͒ and whose emission wavelength was tuned into the technologically important 1.55 m telecommunication wavelength region through the insertion of ultrathin GaAs interlayers beneath the QDs. 9 In this letter, we demonstrate the formation of multilayer-stacked linear InAs QD arrays on the InAs/ InGaAsP SL template on InP ͑100͒ demonstrating a fully self-ordered three-dimensional QD crystal. Identical emission wavelength of the stacked QD arrays is achieved by increasing the thickness of the GaAs interlayer in successive layers.…”

“…The QD arrays are a͒ aligned along the elastically soft ͓001͔ direction to minimize the strain energy, 13,14 which is selected by the miscut of the substrate with steps in the same direction. 9 InAs amount and growth rate, cap layer thickness, annealing temperature, and number of SL template periods are optimized for selforganized ordering due to anisotropic adatom surface migration during annealing and lateral and vertical strain correlations during stacking. Strain correlated stacking of the QD arrays separated by 16 nm Q1.25 manifests itself by the maintenance of linear ordering.…”