Lecture

Quantum Dots: Optical Properties and Applications

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PHYS-434: Physics of photonic semiconductor devices

Series of lectures covering the physics of quantum heterostructures, dielectric microcavities and photonic crystal cavities as well as the properties of the main light emitting devices that are light-emitting diodes (LEDs) and laser diodes (LDs). ...

Description

This lecture explores the optical properties and applications of Stranski-Krastanov quantum dots (QDs), focusing on the InAs/GaAs system. It covers the confined electronic levels, optical properties of QD ensembles, biexciton-exciton cascade, and single photon emission. The historical interest in nanostructures, current advancements, and the ability to tailor optical properties through size, shape, and morphology are discussed. The lecture also delves into the artificial atom concept, electronic states, wavefunction imaging, and the alignment of electrons and holes in QDs. Moreover, it examines the linewidth broadening mechanisms, single photon emitters, and the generation of single photons from quantum dots.

Instructors (2)

Nicolas Grandjean

Nicolas Grandjean received a PhD degree in physics from the University ofNice Sophia Antipolis in 1994 and shortly thereafter joined the French National Center for Scientific Research (CNRS) as a permanent staff member. In 2004, he was appointed tenure-track assistant professor at the École polytechnique fédérale de Lausanne (EPFL) where he created the Laboratory for advanced semiconductors for photonics and electronics. He was promoted to full professor in 2009. He was the director of the Institute of Condensed Matter Physics from 2012 to 2016 and then moved to the University of California at Santa Barbara where he spent 6 months as a visiting professor. Since 2018, he is the head of the School of Physics at the EPFL. He was awarded the Sandoz Family Foundation Grant for Academic Promotion, received the “Nakamura Lecturer” Award in 2010, the "Quantum Devices Award” at the 2017 Compound Semiconductor Week, and “2016 best teacher” award from the EPFL Physics School. His research interests are focused on the physics of nanostructures and III-V nitride semiconductor quantum photonics.

Raphaël Butté

Raphaël Butté was born in Paris, France, in 1973. He received the PhD degree from the University Claude Bernard, Lyon, France, in 2000 for his research on the structural and optoelectronic properties of hydrogenated nanostructured silicon thin films with potential applications for photovoltaics and thin film transistors. He then moved to the University of Sheffield (2000-2003), UK, to work as postdoctoral research associate in the group of Prof. Maurice S. Skolnick (Fellow of the Royal Society). His research shifted to the optical properties of III-V semiconductors with a main focus on the nonlinear optical properties of cavity polaritons occurring in GaAs-based microcavities driven under resonant optical excitation. In 2004, he moved to Ecole Polytechnique Fédérale de Lausanne (EPFL) as scientific collaborator in charge of optical spectroscopy at LASPE (http://laspe.epfl.ch/), a newly established laboratory directed by Prof. Nicolas Grandjean. In 2010, he became permanent member of staff (Scientific Collaborator and Lecturer). He was promoted to the position of Senior Scientist in 2016. His current research activity deals with planar waveguides, microdisks and photonic crystals made from III-nitride semiconductors. In particular, he is leading the activity focusing on: (i) the physics of exciton-polaritons in planar waveguides and (ii) high-β photonic crystal nanolasers. He is the author of 119 scientific articles published in peer-reviewed international journals, 14 publications published in peer reviewed journals following an international conference (Web of Science > 4500 citations, h-index: 36; Google Scholar > 6200 citations, h-index: 42) and 6 book chapters. He has given 30 invited talks in International Conferences/Winter-Summer Schools/Workshops. He has been the Publications Chair/Guest Editor of the Proceedings of the 5th International Workshop on Nitride semiconductors (IWN2008) and also served as Scientific Secretary of IWN2008 and of the 5th International Conference on Spontaneous Coherence in Excitonic Systems (ICSCE5). In 2012, he was one of the 149 scientists recognized by the Outstanding Referee program (http://publish.aps.org/OutstandingReferees) of the American Physical Society (APS) selected from a pool of roughly 60,000 currently active referees. Since September 2019, he is an Editorial Board Member of the newly launched open access APS journal, Physical Review Research. From September 2013 until December 2017, he was one of the Editors of the journal "Superlattices and Microstructures" (Elsevier). Since September 2015 he is a member of the Physics Doctoral School Teaching Committee. He was also a member of the EPFL Teaching Conference from September 2015 until August 2017.

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Ontological neighbourhood

Electrical engineering

Photonics: Topics in photonics

Related concepts (32)

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.

Quantum dot display

A quantum dot display is a display device that uses quantum dots (QD), semiconductor nanocrystals which can produce pure monochromatic red, green, and blue light. Photo-emissive quantum dot particles are used in LCD backlights or display color filters. Quantum dots are excited by the blue light from the display panel to emit pure basic colors, which reduces light losses and color crosstalk in color filters, improving display brightness and color gamut.

Indium gallium arsenide

Indium gallium arsenide (InGaAs) (alternatively gallium indium arsenide, GaInAs) is a ternary alloy (chemical compound) of indium arsenide (InAs) and gallium arsenide (GaAs). Indium and gallium are group III elements of the periodic table while arsenic is a group V element. Alloys made of these chemical groups are referred to as "III-V" compounds. InGaAs has properties intermediate between those of GaAs and InAs. InGaAs is a room-temperature semiconductor with applications in electronics and photonics.

Gallium arsenide

Gallium arsenide (GaAs) is a III-V direct band gap semiconductor with a zinc blende crystal structure. Gallium arsenide is used in the manufacture of devices such as microwave frequency integrated circuits, monolithic microwave integrated circuits, infrared light-emitting diodes, laser diodes, solar cells and optical windows. GaAs is often used as a substrate material for the epitaxial growth of other III-V semiconductors, including indium gallium arsenide, aluminum gallium arsenide and others.

Photon

A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless, so they always move at the speed of light in vacuum, 299792458m/s (or about ). The photon belongs to the class of boson particles. As with other elementary particles, photons are best explained by quantum mechanics and exhibit wave–particle duality, their behavior featuring properties of both waves and particles.

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