RT journal article
T1 Effect of the AlAs capping layer thickness on the structure of InAs/GaAs QD
A1 Ruiz Marín, Nazaret
A1 Fernández de los Reyes, Daniel
A1 Stanojevic, L.
A1 Ben Fernández, Teresa
A1 Braza Blanco, María Verónica
A1 Gallego-Carro, A.
A1 Barcena González, Guillermo
A1 Ulloa, J.M.
A1 González Robledo, David
A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
A2 Ingeniería Informática
K1 (S)TEM
K1 AlAs capping
K1 InAs quantum dots
AB Recently, very thin AlAs capping layers (CLs) have been proposed as a useful tool to increase the performance of InAs/GaAs quantum dot (QDs) devices. However, the structure of QDs after AlAs deposition remains poorly understood and the mechanisms to explain it are often contradictory. In this work, the structural and compositional changes of InAs QDs using different AlAs CL thicknesses have been studied by state-of-the-art STEM-related techniques. First, the heights and In contents of InAs QDs progressively increase with the CL thickness, demonstrating that the AlAs capping produces a strong shielding effect against the decomposition of QDs. However, QD populations for CL thicknesses above 5 ML split into a bimodal distribution in which smaller lenticular QDs cohabit with bigger truncated pyramids. Second, the actual Al contents around the QDs are well below the nominal design, but increasing for thicker CLs. Its distribution is initially non-uniform, tending to accumulate on the flanks of the QDs to the detriment of the apex. Only for thicknesses above 2 ML the Al contents around the QDs start to be similar to those in the regions between the QDs, behaving as a continuous film without irregularities from 5 ML onwards. © 2021 The Author(s)
PB ELSEVIER
SN 0169-4332
YR 2022
FD 2022-01
LK http://hdl.handle.net/10498/25768
UL http://hdl.handle.net/10498/25768
LA eng
NO The work has been co-financed by the Spanish National Research Agency (AEI projects MAT2016-77491-C2-2-R and PID2019-106088RB-C33), Regional Government of Andalusia (project FEDER-UCA18-108319) and the European Regional Development Fund (ERDF).
DS Repositorio Institucional de la Universidad de Cádiz
RD 06-nov-2026