Publication

Three-dimensional nanoscale study of Al segregation and quantum dot formation in GaAs/AlGaAs core-shell nanowires

Anna Fontcuberta i Morral, Martin Heiss, Eleonora Russo, Sonia Conesa Boj, Luca Francaviglia, Yannik Fontana
2014
Journal paper

Abstract

GaAs/Al-GaAs core-shell nanowires fabricated by molecular beam epitaxy contain quantum confining structures susceptible of producing narrow photoluminescence (PL) and single photons. The nanoscale chemical mapping of these structures is analyzed in 3D by atom probe tomography (APT). The study allows us to confirm that Al atoms tend to segregate within the AlGaAs shells towards the vertices of the hexagons defining the nanowire cross section. We also find strong alloy fluctuations remaining AlGaAs shell, leading occasionally to the formation of quantum dots (QDs). The PL emission energies predicted in the framework of a 3D effective mass model for a QD analyzed by APT and the PL spectra measured on other nanowires from the same growth batch are consistent within the experimental uncertainties. (C) 2014 AIP Publishing LLC.

Official source

https://infoscience.epfl.ch/record/205473?ln=en

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Ontological neighbourhood

Electrical engineering

Photonics: Topics in photonics

Related concepts (18)

Quantum dot

Quantum dots (QDs) – also called semiconductor nanocrystals, are semiconductor particles a few nanometres in size, having optical and electronic properties that differ from those of larger particles as a result of quantum mechanics. They are a central topic in nanotechnology and materials science. When the quantum dots are illuminated by UV light, an electron in the quantum dot can be excited to a state of higher energy. In the case of a semiconducting quantum dot, this process corresponds to the transition of an electron from the valence band to the conductance band.

Nanowire

A nanowire is a nanostructure in the form of a wire with the diameter of the order of a nanometre (10−9 metres). More generally, nanowires can be defined as structures that have a thickness or diameter constrained to tens of nanometers or less and an unconstrained length. At these scales, quantum mechanical effects are important—which coined the term "quantum wires". Many different types of nanowires exist, including superconducting (e.g. YBCO), metallic (e.g. Ni, Pt, Au, Ag), semiconducting (e.g.

Molecular-beam epitaxy

Molecular-beam epitaxy (MBE) is an epitaxy method for thin-film deposition of single crystals. MBE is widely used in the manufacture of semiconductor devices, including transistors, and it is considered one of the fundamental tools for the development of nanotechnologies. MBE is used to fabricate diodes and MOSFETs (MOS field-effect transistors) at microwave frequencies, and to manufacture the lasers used to read optical discs (such as CDs and DVDs). Original ideas of MBE process were first established by K.

Related publications (33)

Doping challenges and pathways to industrial scalability of III–V nanowire arrays

Anna Fontcuberta i Morral, Lucas Güniat, Valerio Piazza, Wonjong Kim

Semiconductor nanowires (NWs) have been investigated for decades, but their application into commercial products is still difficult to achieve, with triggering causes related to the fabrication cost and structure complexity. Dopant control at the nanoscale ...

2021

Facet-driven formation of axial and radial In(Ga)As clusters in GaAs nanowires

Anna Fontcuberta i Morral, Lucas Güniat, Santhanu Panikar Ramanandan, Didem Dede, Martin George Friedl, Jean-Baptiste Leran, Wonjong Kim, Nicolas Tappy, Akshay Balgarkashi

Embedding quantum dots in nanowires (NWs) constitutes one promising building block for quantum photonic technologies. Earlier attempts to grow InAs quantum dots on GaAs nanowires were based on the Stranski-Krastanov growth mechanism. Here, we propose a nov ...

IOP PUBLISHING LTD2020

Increasing Functionality of III-V Nanowires on Silicon Substrates

Wonjong Kim

Progress in nanotechnology, including fabrication and characterization tools, opened up the unprecedented low dimensional materials era, where we can manipulate and structure matter on a size scale that we could not reach before. Due to many interesting pr ...

EPFL2020

Related MOOCs (3)

Micro and Nanofabrication (MEMS)

Learn the fundamentals of microfabrication and nanofabrication by using the most effective techniques in a cleanroom environment.

Microstructure Fabrication Technologies I

Learn the fundamentals of microfabrication and nanofabrication by using the most effective techniques in a cleanroom environment.

Micro and Nanofabrication (MEMS)

Learn the fundamentals of microfabrication and nanofabrication by using the most effective techniques in a cleanroom environment.

Graph Chatbot

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.