Towards 3D characterisation of site-controlled InGaAs pyramidal QDs at the nanoscale

TY - JOUR

T1 - Towards 3D characterisation of site-controlled InGaAs pyramidal QDs at the nanoscale

AU - Holsgrove, Kristina M.

AU - O’Reilly, Tamsin I.

AU - Varo, Simone

AU - Gocalinska, Agnieszka

AU - Juska, Gediminas

AU - Kepaptsoglou, Demie M.

AU - Pelucchi, Emanuele

AU - Arredondo, Miryam

N1 - © The Author(s) 2022

PY - 2022/8/30

Y1 - 2022/8/30

N2 - In this work, we report an extensive investigation via transmission electron microscopy (TEM) techniques of InGaAs/GaAs pyramidal quantum dots (PQDs), a unique site-controlled family of quantum emitters that have proven to be excellent sources of single and entangled photons. The most striking features of this system, originating from their peculiar fabrication process, include their inherently 3-dimensional nature and their interconnection to a series of nanostructures that are formed alongside them, such as quantum wells and quantum wires. We present structural and chemical data from cross-sectional and plan view samples of both single and stacked PQDs structures. Our findings identify (i) the shape of the dot, being hexagonal and not triangular as previously assumed, (ii) the chemical distribution at the facets and QD area, displaying clear Indium diffusion, and (iii) a near absence of Aluminium (from the AlAs marker) at the bottom of the growth profile. Our results shed light on previously unreported structural and chemical features of PQDs, which is of extreme relevance for further development of this family of quantum emitters.

AB - In this work, we report an extensive investigation via transmission electron microscopy (TEM) techniques of InGaAs/GaAs pyramidal quantum dots (PQDs), a unique site-controlled family of quantum emitters that have proven to be excellent sources of single and entangled photons. The most striking features of this system, originating from their peculiar fabrication process, include their inherently 3-dimensional nature and their interconnection to a series of nanostructures that are formed alongside them, such as quantum wells and quantum wires. We present structural and chemical data from cross-sectional and plan view samples of both single and stacked PQDs structures. Our findings identify (i) the shape of the dot, being hexagonal and not triangular as previously assumed, (ii) the chemical distribution at the facets and QD area, displaying clear Indium diffusion, and (iii) a near absence of Aluminium (from the AlAs marker) at the bottom of the growth profile. Our results shed light on previously unreported structural and chemical features of PQDs, which is of extreme relevance for further development of this family of quantum emitters.

U2 - 10.1007/s10853-022-07654-2

DO - 10.1007/s10853-022-07654-2

M3 - Article

SN - 0022-2461

JO - Journal of Materials Science

JF - Journal of Materials Science

ER -