Controlled InAs quantum dot nucleation on faceted nanopatterned pyramids

Abstract

The selective quantum dot (QD) nucleation on nanofaceted GaAs pyramidal facets is explored. The GaAs pyramids, formed on a SiO2 masked (001) GaAs substrate, are characterized by well-defined equilibrium crystal shapes (ECSs) defined by three crystal plane families including {11n}, {10n}, and (001). Subsequent patterned QD (PQD) nucleation on the GaAs pyramidal facets is highly preferential towards the (11n) planes due to superior energy minimization. The GaAs pyramid ECS and PQDs are examined using high-resolution scanning electron microscopy and room temperature photoluminescence.

Controlling polarization anisotropy of site-controlled InAs/InP (100) quantum dots

“…In general, for the larger pyramid top areas ͑pyramid bases͒, the QDs nucleate on the high-index ͕103͖ and ͕115͖ facets surrounding a ͑100͒ center facet. 7,13 ber decreases and close to pinch-off single QDs form on the symmetric diamond-shaped ͑100͒ top facet. For higher growth temperature the QDs strongly elongate along ͓011͔ and number and size increase.…”

“…[1][2][3] The envisioned devices such as cavity enhanced single and entangled photon sources 4,5 require precise site control of the QDs. This has been achieved by growth on truncated pyramids, [6][7][8] in V-grooves, 4,9 and nanoholes 10,11 for InAs/ GaAs and InAs/InP QDs with emission in the important 1.55 m telecom wavelength region. 12,13 In addition, control of the QD shape and consequently linear polarization of the emission is crucial for entangled photon sources.…”

Planarization of InP pyramids containing integrated InAs quantum dots and their optical properties

“…2 Pushing photonic integration technology to the fundamental limits regarding component size, complexity, and power consumption will require position control of QDs in small numbers, down to a single QD and novel integration techniques allowing device operation at the few/single electron and photon levels. Among the various approaches for QD position control based on growth on patterned substrates [3][4][5][6] and selective area growth [7][8][9][10][11][12][13] we have chosen the latter. The deposition of QDs on selectively grown pyramids allows not only QD position and number control but also the control of the QD distribution through the pyramids base shape 12 for matching it, e.g., to the optical mode of a particular photonic crystal nanocavity.…”

Distribution control of 1.55μm InAs quantum dots down to small numbers on truncated InP pyramids grown by selective area metal organic vapor phase epitaxy

“…This is due to the preferential nucleation of the QDs on the high-index facets. Similar to InAs QDs on GaAs pyramids, 8 it is believed that the high-index facets allow optimal strain relaxation. When changing the shape of the pyramid base from circular to elliptical, the relative size of the ͕103͖ and ͕115͖ facets is reduced with the aspect ratio, as shown in Figs.…”

“…For advanced quantum functional devices such as nanolasers and single photon sources, however, precise position and number control of a few down to a single QD are required. This can be realized by predefined QD nucleation on truncated pyramids formed by selective area growth in dielectric mask openings [3][4][5][6][7] and has been demonstrated for the InAs/ GaAs material system by metal organic vapor phase epitaxy ͑MOVPE͒ 4,8,9 and molecular beam epitaxy and for the InAs/ InP material system by chemical beam epitaxy 5 and MOVPE. 3 Moreover, for efficient nanolasers and single photon sources employing highquality microcavities such as disks, rings, or photonic crystal defects, control of the QD distribution is highly desirable to maximize the overlap with the photon field of a specific optical mode with certain size and shape.…”