Dr. Simon Fafard Profile

Dr. Simon Fafard

Co-founder & President at Broadcom Corp

SPIE Involvement:

Author

Publications (19)

Proceedings Article | 19 April 2017 Presentation

20-junction photonic power converter performance under non-uniform illumination calculated by 3D distributed circuit model (Conference Presentation)

Sanmeet Chahal, Mathew Wilkins, Denis Masson, Simon Fafard, Christopher Valdivia, Karin Hinzer

Proceedings Volume 10099, 1009908 (2017) https://doi.org/10.1117/12.2252919

KEYWORDS: Mathematical modeling, Resistors, 3D modeling, Circuit switching, Photovoltaics, Instrument modeling, Performance modeling, Computer simulations, Solar cells, Optimization (mathematics)

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SPIE Journal Paper | 7 April 2017

Design of thin InGaAsN(Sb) n-i-p junctions for use in four-junction concentrating photovoltaic devices

Matthew Wilkins, James Gupta, Abdelatif Jaouad, Boussairi Bouzazi, Simon Fafard, Abderraouf Boucherif, Christopher Valdivia, Richard Arès, Vincent Aimez, Henry Schriemer, Karin Hinzer

JPE, Vol. 7, Issue 02, 022502, (April 2017) https://doi.org/10.1117/12.10.1117/1.JPE.7.022502

KEYWORDS: Sun, Gallium arsenide, Doping, Diffusion, Germanium, Resistance, Solar concentrators, Solar cells, Semiconducting wafers, Annealing

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Proceedings Article | 14 March 2016 Paper

Advances with vertical epitaxial heterostructure architecture (VEHSA) phototransducers for optical to electrical power conversion efficiencies exceeding 50 percent

S. Fafard, F. Proulx, M. C. A. York, M. Wilkins, C. Valdivia, M. Bajcsy, D. Ban, A. Jaouad, B. Bouzazi, R. Arès, V. Aimez, K. Hinzer, D. Masson

Proceedings Volume 9743, 974304 (2016) https://doi.org/10.1117/12.2218486

KEYWORDS: Heterojunctions, Measurement devices, Temperature metrology, Quantum efficiency, Diodes, External quantum efficiency, Gallium arsenide, Absorption, Semiconductor lasers, Platinum

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Proceedings Article | 14 March 2016 Paper

Enhanced photocarrier extraction mechanisms in ultra-thin photovoltaic GaAs n/p junctions

Mark C. A. York, Francine Proulx, Denis Masson, Abdelatif Jaouad, Boussairi Bouzazi, Richard Arès, Vincent Aimez, Simon Fafard

Proceedings Volume 9743, 97430Y (2016) https://doi.org/10.1117/12.2212960

KEYWORDS: Photovoltaics, Gallium arsenide, Optoelectronic devices, Optoelectronics, Heterojunctions, TCAD, Instrument modeling, Quantum efficiency, Electroluminescent displays, Measurement devices, Indium gallium phosphide, Data modeling

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Proceedings Article | 14 March 2016 Paper

Performance impact of luminescent coupling on monolithic 12-junction phototransducers for 12 V photonic power systems

Matthew Wilkins, Christopher Valdivia, Sanmeet Chahal, Masanori Ishigaki, Denis Masson, Simon Fafard, Karin Hinzer

Proceedings Volume 9743, 97430W (2016) https://doi.org/10.1117/12.2213727

KEYWORDS: Photovoltaics, Gallium arsenide, Manufacturing, Quantum efficiency, Multijunction solar cells, Heterojunctions, Photonic devices, Indium gallium phosphide, Physics, Silicon carbide, Field effect transistors, Diodes

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Proceedings Article | 16 March 2015 Paper

Five-volt vertically-stacked, single-cell GaAs photonic power converter

Christopher Valdivia, Matthew Wilkins, Boussairi Bouzazi, Abdelatif Jaouad, Vincent Aimez, Richard Arès, Denis Masson, Simon Fafard, Karin Hinzer

Proceedings Volume 9358, 93580E (2015) https://doi.org/10.1117/12.2079824

KEYWORDS: External quantum efficiency, Gallium arsenide, Sensors, Absorption, Photons, Optical simulations, Image segmentation, Photovoltaics, Device simulation, Quantum efficiency

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Proceedings Article | 23 September 2010 Paper

Thermal test and simulation of alumina receiver with high efficiency multi-junction solar cell for concentrator systems

Simon Chow, Christopher Valdivia, Jeffrey Wheeldon, Richard Ares, Osvaldo Jesus Arenas, Vincent Aimez, David McMeekin, Simon Fafard, Karin Hinzer

Proceedings Volume 7750, 775035 (2010) https://doi.org/10.1117/12.872894

KEYWORDS: Solar cells, Receivers, Sun, Solar concentrators, Multijunction solar cells, Calibration, Temperature metrology, Computer simulations, Copper, Device simulation

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Proceedings Article | 23 September 2010 Paper

High-efficiency commercial grade 1cm2 AlGaInP/GaAs/Ge solar cells with embedded InAs quantum dots for concentrator demonstration system

J. Wheeldon, C. Valdivia, D. Masson, F. Proulx, B. Riel, N. Puetz, E. Desfonds, S. Fafard, B. Rioux, A. SpringThorpe, R. Arès, V. Aimez, M. Armstrong, M. Swinton, J. Cook, F. Shepherd, T. Hall, K. Hinzer

Proceedings Volume 7750, 77502Q (2010) https://doi.org/10.1117/12.872890

KEYWORDS: Solar cells, Solar energy, Solar concentrators, Quantum dots, Quantum efficiency, Reliability, Absorption, Sun, Indium arsenide, Resistance

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Proceedings Article | 23 September 2010 Paper

Time-dependent analysis of AlGaAs/AlGaAs tunnel junctions for high efficiency multi-junction solar cells

Gitanjali Kolhatkar, Jeffrey Wheeldon, Christopher Valdivia, Alexandre Walker, Simon Fafard, Artur Turala, Abdelatif Jaouad, Richard Arès, Vincent Aimez, Karin Hinzer

Proceedings Volume 7750, 77502S (2010) https://doi.org/10.1117/12.872886

KEYWORDS: Resistance, Solar cells, Oscilloscopes, Multijunction solar cells, Time metrology, Doping, Remote sensing, Power supplies, Calibration, Germanium

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Proceedings Article | 12 August 2008 Paper

Optimization of antireflection coating design for multijunction solar cells and concentrator systems

Christopher Valdivia, Eric Desfonds, Denis Masson, Simon Fafard, Andrew Carlson, John Cook, Trevor Hall, Karin Hinzer

Proceedings Volume 7099, 709915 (2008) https://doi.org/10.1117/12.807675

KEYWORDS: Solar cells, Antireflective coatings, Coating, Refractive index, Silicon, Solar concentrators, Absorption, Photovoltaics, Multijunction solar cells, Ultraviolet radiation

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Proceedings Article | 14 June 2004 Paper

Dephasing processes in InGaAs quantum dots and quantum-dot molecules

Paola Borri, Wolfgang Langbein, S. Schneider, Ulrike Woggon, Markus Schwab, Manfred Bayer, Roman Sellin, Dongxun Ouyang, Dieter Bimberg, S. Fafard, Zbigniew Wasilewski, Pawel Hawrylak

Proceedings Volume 5361, (2004) https://doi.org/10.1117/12.531544

KEYWORDS: Excitons, Quantum dots, Phonons, Molecules, Signal detection, Indium gallium arsenide, Picosecond phenomena, Temperature metrology, Polarization, Acoustics

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Proceedings Article | 11 June 2003 Paper

Entangled exciton states in quantum dot molecules

M. Bayer, G. Ortner, A. Larionov, A. Kress, Alfred Forchel, Pawel Hawrylak, K. Hinzer, M. Korkusinski, Simon Fafard, Zbigniew Wasilewski, Thomas Reinecke, Yu. Lyanda-Geller

Proceedings Volume 5023, (2003) https://doi.org/10.1117/12.514621

KEYWORDS: Quantum dots, Molecules, Excitons, Gallium arsenide, Particles, Chemical species, Quantum communications, Quantum optics, Quantum information, Quantum computing

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Currently there is strong interest in realizing implementations of quantum computation and quantum cryptography in a solid state environment. One of the systems that are actively studied are semiconductor quantum dots (QDs). Due to their discrete energy level structure, they are often called artificial atoms, and they attract immediately interest of quantum information science since they allow to mimic the design developed for atomic physics systems such as ions in traps or atoms in cavities. However, despite of the similarities, one has to keep in main that any elementary excitation in a QD has a generic many-body character. An essential building block of a quantum processor is a quantum gate which entangles the states of two quantum bits. Recently it has been proposed that a pair of vertically aligned QDs could be used as an optically driven quantum gate: The quantum bits are individual carriers either on dot zero or dot one. The different dot indices play the same role as a "spin," therefore we term them "isospin." Quantum mechanical tunneling between the dots rotates the "isospin" and leads to superposition of two quantum dot states. The quantum gate is built when two different particles, an electron and a hole, are created optically. The two particles form entangled isospin states. The entanglement can be controlled by application of an electric field along the heterostructure growth direction. Here we present spectroscopic studies on single quantum dot molecules (QDMs) with different vertical separation between the dots that support the feasibility of this proposal. The comparison of the evolution of the excitonic recombination spectrum with the results of calculations allows us to demonstrate coherent tunneling of electrons and holes across the separating barrier and the formation of entangled exciton states. For a given barrier width, we find only small variations of the tunneling induced splitting between the entangled states demonstrating a good homogeneity within the obtained QDM ensembles.

Proceedings Article | 17 February 2003 Paper

Dynamics of photo-excited carriers in self-assembled quantum dots

Denis Morris, Nathalie Perret, Daria Riabinina, Jean Beerens, Vincent Aimez, Jacques Beauvais, Simon Fafard

Proceedings Volume 4833, (2003) https://doi.org/10.1117/12.473944

KEYWORDS: Picosecond phenomena, Gallium arsenide, Quantum dots, Diffusion, Crystals, Doping, Phonons, Scattering, Carrier dynamics, Luminescence

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Proceedings Article | 12 June 2002 Paper

Quantum dot infrared photodetector

Hui Liu, Simon Fafard, Richard Dudek, Zbigniew Wasilewski

Proceedings Volume 4646, (2002) https://doi.org/10.1117/12.470504

KEYWORDS: Quantum well infrared photodetectors, Quantum dots, Electrons, Doping, Infrared photography, Infrared radiation, Photodetectors, Absorption, Phonons, Gallium arsenide

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Proceedings Article | 15 December 2000 Paper

Single-dot spectroscopy of multiexcitons in AlInAs/AlGaAs quantum dots

Karin Hinzer, M. Bayer, O. Stern, A. Gorbunov, Alfred Forchel, Pawel Hawrylak, Jean Lapointe, Simon Fafard

Proceedings Volume 4087, (2000) https://doi.org/10.1117/12.406453

KEYWORDS: Excitons, Magnetism, Luminescence, Spectroscopy, Quantum dots, Chemical species, Indium arsenide, Gallium arsenide, Quantum communications, Nanostructures

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Proceedings Article | 15 December 2000 Paper

Quantum dot intermixing with thermal and laser annealing

C. Allen, Jan Dubowski, Paul Piva, Simon Fafard

Proceedings Volume 4087, (2000) https://doi.org/10.1117/12.406366

KEYWORDS: Annealing, Diffusion, Quantum dots, Gallium arsenide, Luminescence, Indium arsenide, Temperature metrology, Nd:YAG lasers, Nanostructures, Photonic devices

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Proceedings Article | 11 July 2000 Paper

Quantum dot devices

Simon Fafard, Hui Liu, Zbigniew Wasilewski, John McCaffrey, M. Spanner, Sylvain Raymond, C. Allen, Karin Hinzer, Jean Lapointe, C. Struby, Ming Gao, Pawel Hawrylak, C. Gould, A. Sachrajda, P. Zawadzki

Proceedings Volume 4078, (2000) https://doi.org/10.1117/12.392130

KEYWORDS: Quantum dots, Spectroscopy, Gallium arsenide, Semiconductor lasers, Indium arsenide, Transmission electron microscopy, Optical storage, Luminescence, Electrons, Quantum wells

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From a recent study of the growth and optical properties of quantum dots (QD's), we demonstrated that artificial atoms with sharp electronic shells can be fabricated with good control, using self-assembled QD's grown by molecular beam epitaxy. Size and shape engineering of the QD's during growth permits the tailoring of their intersublevel energy spacings. We demonstrate a much improved uniformity of the macroscopic ensembles of QD's, with well-resolved electronic shells. In addition to size and shape engineering of the QDS's in the case of single-layer samples, we demonstrate significant improvements in the uniformity of the vertically self-aligned stacked QD's. State-filling spectroscopy of the zero-dimensional transitions between confined electrons and holes demonstrates that the energy levels are readily tunable. One to five confined levels, with an inter-level energy spacing between 25 and 90 meV, are obtained by adjusting the growth temperature or with post-growth annealings. Such QD's having well-defined excited-states have been grown in the active region of devices and results will be presented for lasers, detectors, or for structures displaying optical memory effects. For example, QD laser diodes with well-defined electronic shells are fabricated, and shape-engineered stacks of self-aligned QD's are used to increase the gain in the active region. Lasing is observed in the upper QD shells for small gain media, and progresses towards the QD ground states for longer cavity lengths. We obtained at 77K thresholds for J_th=15 A/cm² for a 2 mm cavity lasing in the first excited state (p-shell), and at 300K for a 5 mm cavity, J_th is ~430A/cm² with lasing in the d-shell. For an increased QD density, J_th is smaller than 100A/cm² at room temperature. For inter- sublevel transitions, we demonstrated broadband normal incidence detection with responsivity approaching 1A/W at a detection wavelength of 5 microns. For interband detection, the photoluminescence decay time of p-i-n diode can be changed from ~3nsec to ~0.3nsec (3Ghz) with a reverse bias. For Qds capped with less than ~10 nm, remarkable charge transfers between QD and surface states lead to optical memory effects lasting over time-scales of several minutes.

Proceedings Article | 4 December 1998 Paper

Visible quantum dots under reversed bias

Fang Yang, Geof Aers, Karin Hinzer, Yan Feng, Simon Fafard, John McCaffrey, N. Sylvain Charbonneau, Anthony SpringThorpe

Proceedings Volume 3491, (1998) https://doi.org/10.1117/12.328735

KEYWORDS: Quantum dots, Electroluminescence, Temperature metrology, Data modeling, Laser damage threshold, Photodetectors, Cladding, Picosecond phenomena, Luminescence, Transmission electron microscopy

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Proceedings Article | 4 December 1998 Paper

Towards quantum dot laser diodes emitting at 1.5 microns

Simon Fafard, John McCaffrey, Yan Feng, C. Allen, Hugues Marchand, L. Isnard, Patrick Desjardins, S. Guillon, Remo Masut

Proceedings Volume 3491, (1998) https://doi.org/10.1117/12.328737

KEYWORDS: Indium arsenide, Heterojunctions, Laser damage threshold, Electroluminescence, Quantum dot lasers, Diodes, Gallium arsenide, Transmission electron microscopy, Semiconductor lasers, Quantum wells

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