SUNLAB News
SUNLAB spin-off Enurgen wins PitchFest Throw Down at SaaS North Conference
Congrulations to our friends at Enurgen, and particularly its CEO, Kibby Pollack, for winning first place at the SAAS North Conference PitchFest Final Throw Down last week in Ottawa. Click here and here for details and pictures.
Enurgen is a start-up born from the SUNLAB’s work in bifacial cell-to-system modelling. It is helping to bring about the global transition to a zero-carbon future by leveraging its advanced modelling software to help generate clean, renewable, sustainable energy to power today’s electric grids. The start-up is made up of former and current graduate students, researchers, and professors from the SUNLAB.
New Position at the SUNLAB: Photonic Power Converters - Study of Luminescent Coupling
The SUNLAB at the University of Ottawa is announcing one position for a new graduate student.
The SUNLAB
The SUNLAB, Canada’s premier solar cell characterization research facility focusing on high performance devices and specializing in solar energy, optoelectronics, and photonics, was founded by Karin Hinzer in 2007. Housed at the Nexus for Quantum Technologies Institute at the University of Ottawa, it brings together physicists, engineers, chemists, and materials scientists in an interdisciplinary and collaborative environment.
Research Project
Photonic power converters (PPCs) are photovoltaic devices that generate electric power from laser light in power-by-light systems. State of the art PPCs contain multiple absorbing semiconductor pn junctions that are vertically stacked and connected in series, allowing the output voltage of the device to be scaled for a target application. Under high intensity laser irradiation, light is radiated from overproducing junctions and reabsorbed in limiting junctions in a process known as luminescent coupling. The selected candidate will study the luminescent coupling process in multi-junction PPCs using experimental and numerical techniques.
The candidate will perform experimental measurements under high-powered laser illumination to characterize luminescent coupling between the junctions. Concurrently, they will develop a surrogate model to predict the luminescent coupling behaviour using artificial intelligence (AI) methodologies. The surrogate model will build upon existing models developed within the SUNLAB research group. These models include transfer matrix methods developed in Python and drift-diffusion models performed in Synopsys Sentaurus TCAD. Following development and validation of the surrogate AI model against experimental data, they will use the model to generate an optimized multi-junction PPC design for 1550 nm operation in free-space power beaming systems with 3-5 V output voltages and high-power conversion efficiencies.
The work will be undertaken in the SUNLAB photovoltaic characterization facility, located in the Advanced Research Complex at the University of Ottawa. The candidate will have access to high-powered computing machines. The selected candidate will gain hands-on experience in optoelectronic device design, simulation, and characterization. The research will constitute part of the candidate’s research thesis.
Eligibility
To be considered for this position, the candidate must successfully apply for admission to the program of MASc or PhD in electrical engineering or physics at the University of Ottawa.
How to Apply
Send your CV and unofficial university transcripts to sunlabadmin@uottawa.ca and khinzer@uottawa.ca. In the subject line, indicate “New Position at the SUNLAB: Photonic Power Converters - Study of Luminescent Coupling”. Only candidates retained for an interview will be contacted.
The SUNLAB embraces diversity and inclusion in the workplace. We are passionate about our people and committed to employment equity. We foster a culture of respect, teamwork and inclusion, where collaboration, innovation, and creativity fuel our quest for research excellence. While all qualified persons are invited to apply, we welcome applications from qualified Indigenous persons, racialized persons, persons with disabilities, women and LGBTQIA2S+ persons. The SUNLAB is committed to creating and maintaining an accessible, barrier-free work environment. The SUNLAB is also committed to working with applicants with disabilities requesting accommodation during the recruitment, assessment and selection processes.
SUNLAB students awarded scholarships
Congratulations to SUNLAB students Alison Clarke, Gavin Forcade and Erin Tonita on receiving prestigious scholarships to support their research.
MSc physics candidate Alison Clarke has been awarded a Canada Graduate Scholarship – Master’s program. This scholarship is meant to develop trainee research skills by “supporting students who demonstrate a high standard of achievement in undergraduate and early graduate studies." Alison is also the recipient of the King’s Medal at University of King’s College, Halifax. This honour is “awarded to the graduating student who stands highest in an arts or science honours program”.
PhD physics candidates Gavin Forcade and Erin Tonita have been awarded a Canada Graduate Scholarships – Michael Smith Foreign Study Supplement. This award supports “high-calibre Canadian graduate students in building global linkages and international networks through the pursuit of exceptional research experiences at research institutions abroad”. This funding is allowing Gavin and Erin to pursue 6-month internships at the National Renewable Energy Laboratory facilities in Golden, Colorado. Gavin’s research is on the optimization of III-V photovoltaics substrate reuse while Erin is designing, assembling, and modelling bifacial vertical arrays under high latitude operating conditions to better understand the conditions under which view factor and ray tracing models deviate in the North.
References
Natural Sciences and Engineering Research Council of Canada (retrieved October 27, 2023). Canada Graduate Scholarships - Master's program. https://www.nserc-crsng.gc.ca/students-etudiants/pg-cs/cgsm-bescm_eng.asp
Natural Sciences and Engineering Research Council of Canada (retrieved October 27, 2023). Canada Graduate Scholarships - Michael Smith Foreign Study Supplements. https://www.nserc-crsng.gc.ca/students-etudiants/pg-cs/cgsforeignstudy-bescetudeetranger_eng.asp
“King’s Medal recipient balances volunteer work with academic success” (retrieved October 27, 2023). University of Kings College, Halifax. https://ukings.ca/news/kings-medal-recipient-balances-volunteer-work-with-academic-success-at-kings/
New publication from the SUNLAB: Nano Letters
A multidisciplinary initiative between the University of Ottawa SUNLAB, Micro and Nano Systems Lab & Krich Lab, Princeton University and Polytechnique Montréal resulted in a recent publication first-authored by PhD candidate Mathieu Giroux, in Nano Letters. In this manuscript, the authors demonstrate the potential of using a silicon nitride (SiN) nanomechanical resonator as a sensing element to study near-field radiative heat transfer.
Near-field radiative heat transfer (NFRHT) has demonstrated great theoretical potential for applications such as energy conversion and heat transfer control. NFRHT consists of evanescent coupling occurring between two bodies at sub-wavelength distances, increasing the radiative heat transfer beyond the conventional laws of thermal radiation. Despite a large amount of promising theoretical work, experimental progress on the topic is relatively scarce due to challenges of precision alignment at high temperature. NFRHT measurements often rely on custom microdevices that can be difficult to reproduce after their original demonstration. In this work, the authors study NFRHT using plain SiN membrane nanomechanical resonators, a widely available substrate used in applications such as electron microscopy and optomechanics and on which other materials can easily be deposited.
Relying on a high precision 5-axis positioning system, a heated spherical sample was aligned with a SiN resonator, enabling radiative heat transfer measurement down to a minimal distance of 180 nm. The NFRHT is measured by tracking the highly temperature-sensitive mechanical resonance frequency of the membrane as the distance between the two surfaces is decreased. Comparison with the theoretical model demonstrate that, at the achieved deep subwavelength distance of 180 nm, the heat transfer is highly dominated by surface polariton resonances over an area comparable to plane-plane experiments employing custom microfabricated devices. This results in a quasi-monochromatic radiative heat transfer, desirable in most NFRHT applications.
The authors expect that the reproducibility and flexibility of this platform will facilitate investigation of new materials for NFRHT – such as graphene, thin-film metals, lossy materials, hyperbolic materials and metamaterials – which can all be easily deposited on SiN membranes. The fact that nanomechanical resonators are sensitive to both force and temperature also creates an opportunity to investigate thermal corrections to the Casimir effect.
Click here for the full article.
M. Giroux, M. Stephan, M. Brazeau, S. Molesky, A. W. Rodriguez, J. J. Krich, K. Hinzer, and R. St-Gelais, Measurement of near-field radiative heat transfer at deep sub-wavelength distances using nanomechanical resonators, Nano Lett. 23 (18), 8490-8497 (2023). DOI: 10.1021/acs.nanolett.3c02049
SUNLAB welcomes new students
The SUNLAB is thrilled to have welcomed many new students these past few months:
PhD electrical engineering candidate Idriss Amadou Ali
PhD civil engineering candidate Milad Nouri Shirdar
MASc electrical engineering candidates Jaskiran Kaur and Derrick Wu
MSc physics candidate Alison Clarke
Undergraduate summer students Nicholas Pulido and Astan Simaga
Undergraduate summer student Victoria Jancowski continuing during the fall
Undergraduate co-op student Elam Olame Mugabo continuing during the fall
Undergraduate physics students working on their fourth year projects Trinity Berube and Andre Pundit
Two groups of electrical engineering students working on their capstone projects:
Eden Kindja Nehema, Jack Redmond, Rikki Romana, Hiruni Senarath
Johny Camara, Jonah Hamer-Wilson, Victoria Johnson, Andre Pundit and Matthew Yakubu
Welcome to all!
Fulcrum interview with SUNLAB student
The Fulcrum, the University of Ottawa’s English-language student newspaper, recently interviewed PhD candidate Erin Tonita about her Joule publication. Erin explains the difference between bifacial and conventional solar panels and demistifies the general illumination method detailed in her paper. Click here for the full interview.
U of O researcher suggests novel measuring method for bifacial solar panels, The Fulcrum, September 21, 2023.
New publication from the SUNLAB: Journal of Materials Chemistry C
A collaboration between the Lessard Research Group and the SUNLAB resulted in a recent publication first-authored by MSc candidate Nicholas Dallaire, in the Journal of Materials Chemistry C. In this manuscript, the authors explore the effect of selective wavelength exposure on single walled carbon nanotube-based thin film transistors.
The fabrication of high-purity semiconducting single-walled carbon nanotubes (sc-SWNTs) often utilizes conjugated polymers to isolate the semiconducting from the metallic species. These polymers preferentially sort and disperse certain sc-SWNT chiralities and often remain wrapped around sc-SWNTs during device integration. In this study, the authors expose three different SWNT-based thin film transistors, each with a different dispersion polymer to three different laser wavelengths selected to overlap both the optical transitions of the sc-SWNTs and the polymer absorption.
The authors show that two phases emerge. An initial soak, where the devices change after an initial exposure which permanently increases the mobility. The second phase, the photo cycling, produces repeatable device performance between exposures “On Cycling” and post exposures “Off Cycling”, such as consistent threshold voltage shifts with an overall average shift of 3.6±0.6 V, highly dependent on the wavelength and polymer, thus providing greater motivation for tunable SWNT-based thin film transistor photodetectors. Although the general behavior is shared among most types and wavelengths, discrepancies in intensity emerge, especially when exciting the polymer. Hence, the authors show the importance of polymer choice when considering desirable parameters, in addition to their selected SWNT chirality. The results of this research will lead to improvements in SWNT-based thin film transistors. Applications include organic photodetectors.
Click here for the full article.
Nicholas J. Dallaire, Brendan Mirka, Joseph G. Manion, William J. Bodnaryk, Darry Fong, Alex Adronov, Karin Hinzer, and Benoît H. Lessard, Conjugated wrapping polymer influences on photoexcitation of single-walled carbon nanotube-based thin film transistors, J. Mater. Chem. C 11, 9161-9171 (2023) DOI: 10.1039/D3TC01484C
SUNLAB at PVSC
Earlier this month, SUNLAB students and researchers attended the 50th IEEE Photovoltaics Specialists Conference in San Juan, Puerto Rico. Postdoctoral fellow Mathieu de Lafontaine, PhD physics candidates Gavin Forcade and Erin Tonita, and PhD electrical engineering Mandy Lewis presented results on a wide range of topics including photonic power converters, bifacial photovoltaic systems, and betavoltaics. For a full list of SUNLAB presentations, see our Conference Presentations page.
Congratulations to:
Mandy Lewis, for being awarded a Best Student Paper Award for Area 7 for the second year in a row;
SUNLAB friend Professor Jacob Krich for receiving the Napkin Award for his work as Area 1 Chair;
Mathieu de Lafontaine for Area 1 Best Poster nomination;
Erin Tonita and Gavin Forcade for being Best Student Presentation Award Finalists;
Gavin Forcade, Mandy Lewis and Erin Tonita for mentions in the Tuesday Daily Highlights;
Mathieu de Lafontaine for mention in the Thursday Daily Highlights.
The IEEE Photovoltaics Specialists Conference is the longest-running technical gathering for the photovoltaics industry. This year, it was held at the Puerto Rico Convention Center in San Juan, Puerto Rico, from June 11 to 16.
Karin Hinzer, Gavin Forcade and Mathieu de Lafontaine posing in front of Mathieu’s poster.
Mandy Lewis
Erin Tonita
Certificate for Mandy Lewis’s Best Student Paper Award.
Plaque for Jacob Krich’s Napkin Award.
SUNLAB at RQMP Grande Conférence
On Friday, June 9, SUNLAB members traveled to Sherbrooke, Québec, to attend the Grande conférence of the Regroupment québécois sur les matériaux de pointe (Québec Network Advanced Materials). SUNLAB director Karin Hinzer was the keynote speaker at the conference. Her talk covered new developments in solar energy and photonic power. PhD candidate Idriss Amadou Ali presented a poster entitled “Developing and packaging a near-IR on chip CO2 sensor”. Postdoctoral fellow Paige Wilson and MASc candidate Derrick Wu also attended the conference.
Idriss Amadou Ali presents his poster to conference participants.
From left to right: Idriss Amadou Ali, Karin Hinzer, Paige Wilson and Derrick Wu.
SUNLAB winter thesis defences
Congratulations to Trevor Coathup, Ras-Jeevan Obhi and Neda Nouri who defended their theses in the last few months! They received their diplomas this weekend at the spring convocation. You can now find their theses on ruor.uottawa.ca. Congratulations also to Idriss Amadou Ali, who recently started his PhD in electrical engineering at the SUNLAB. Idriss received a BSc Physics and BASc Electrical Engineering at the spring convocation.
Trevor Coathup, MASc Electrical Engineering, Effect of torque tube reflection on shading and energy yield in bifacial photovoltaic systems, DOI: 10.20381/ruor-29138
Ras-Jeevan Obhi, MASc Electrical Engineering, Characterizing and modelling quantum dashes for InP-based semiconductor lasers, DOI: 10.20381/ruor-28676
Neda Nouri, PhD Electrical Engineering, Design, modeling, and optimization of thin and ultra-thin photonic power converters operating at 1310 nm laser illumination, DOI: 10.20381/ruor-28539
From left to right: Karin Hinzer, Idriss Amadou Ali, Neda Nouri, and Ras-Jeevan Obhi.
SUNLAB students awarded scholarships
Congratulations to SUNLAB students Mandy Lewis, Erin Tonita, Victoria Jancowski and Nicholas Pulido on receiving prestigious scholarships to support their research.
PhD electrical engineering candidate Mandy Lewis and PhD physics candidate Erin Tonita were each awarded an Ontario Graduate Scholarship. This merit-based scholarship is available to graduate students in all disciplines of academic study. The Ontario Graduate Scholarships program is jointly funded by the Province of Ontario and Ontario universities.
BASc electrical engineering candidate Victoria Jancowski is spending the summer at the SUNLAB performing research on spectroradiometric standards for bifacial photovoltaic solar power. She was awarded a CSA Group Undergraduate Research Scholarship for a second year in a row. This scholarship aims to support undergraduate students in the pursuit of novel research related to standards.
BASc electrical engineering candidate Nicholas Pulido was awarded an Undergraduate Student Research Award from the Natural Sciences and Engineering Research Council of Canada. This scholarship is meant to nurture undergraduate students’ interest and fully develop their potential for a research career. This summer, Nicholas is studying the effects of artificial reflectors on bifacial photovoltaic systems using open-source view-factor models.
References
Ontario Student Assistance Program (retrieved June 9, 2023). Ontario Graduate Scholarship (OGS) Program: https://osap.gov.on.ca/OSAPPortal/en/A-ZListofAid/PRDR019245.html
CSA Group (retrieved June 9, 2023). CSA Group Undergraduate Research Scholarship: https://www.csagroup.org/csa-group-undergraduate-research-scholarship/
NSERC (retrieved June 9, 2023). Undergraduate Student Research Awards: https://www.nserc-crsng.gc.ca/students-etudiants/ug-pc/usra-brpc_eng.asp
New publication from the SUNLAB: Solar Energy
Led by PhD candidate Erin Tonita, SUNLAB researchers have published a new paper in Solar Energy, describing the optimal row spacing of tracked, south-facing fixed-tilt, and east-west vertical photovoltaic (PV) systems as a function of latitude up to 75°N.
Traditional guidelines for determining the layout of PV arrays were historically developed for monofacial fixed-tilt systems at low-to-moderate latitudes. As the PV market progresses toward bifacial technologies, tracked systems, higher latitudes, and land-constrained areas, updated flexible and representational guidelines are required. Old approaches, like the winter solstice rule where row spacing is selected to eliminate direct inter-row shading on December 21 at solar noon, are insufficient to capture the nuance of deployment planning, where practical and economical constraints vary widely both geographically and temporally.
Using their 3D view-factor PV system model, DUET, SUNLAB researchers optimized row spacing for tracked, fixed-tilt, and vertical arrays with both bifacial and monofacial technologies from 17-75°N with acceptable inter-row shading losses of 5-15%. Results were generalized for an arbitrary collector area by presenting the ground coverage ratio (GCR – i.e., the ratio between PV collector length and row pitch). Formulae for calculating the appropriate GCR of a PV deployment between 17-75°N are provided in the article.
GCR varies widely between 0.15-0.68 for fixed-tilt systems compared to 0.17-0.32 for HSAT systems, both with a strong latitude-dependence. Similarly, the optimal tilt of fixed-tilt arrays varies widely from 7° above latitude-tilt to 60° below latitude-tilt, depending on the latitude and GCR. Vertical systems are less sensitive to latitude, with GCR varying from 0.10-0.16 between 17-75°N. In all cases, it was demonstrated that tracked and fixed-tilt PV arrays should have similar GCRs >55°N. Less than 55°N, tracked systems are more sensitive to row-to-row shading losses.
SUNLAB authors additionally found that it is reasonable to approximate the row spacing of bifacial arrays as equivalent to monofacial arrays, with bifacial modules of 96% bifaciality requiring GCRs lower by 0.03 on average than monofacial modules.
Overall, this research provides updated representational and flexible guidelines for PV system design that better suit the expanding PV sector.
Click here for the full article.
E. M. Tonita, A. C. J. Russell, C. E. Valdivia, and K. Hinzer, Optimal ground coverage ratios for tracked, fixed-tilt, and vertical photovoltaic systems for latitudes up to 75°N, Sol. Energy 258, 8-15 (2023). DOI: 10.1016/j.solener.2023.04.038
In the media:
New guidelines for inter-row spacing of PV power plants, pv magazine, July 6, 2023
Graphical abstract
uOttawa, University of Würzburg scientists make breakthrough in study of light
Physicists and physical chemists from the University of Würzburg and the University of Ottawa have solved a decades-old problem of distinguishing single and multiple light excitations.
“Laser light is widely used to learn about many kinds of materials using a broad set of techniques called spectroscopy,” says uOttawa physics and SUNLAB professor, and study co-author Jacob Krich. “We have developed a new spectroscopic method that is easy to apply and gives access to information about what happens when materials absorb more than one photon.”
The interaction of laser light with all kinds of materials is used to learn about biological, chemical and solid-state systems. Frequently, researchers are interested in the behaviour of materials after they’ve been “excited” just once — that is, after they absorb a single photon. To reach this limit, scientists turn down the power in the laser, which makes signals harder to measure and noisier.
The method developed by the team of physicists and physical chemists has a broad range of applications. It would be particularly useful in studying systems with closely-packed light absorbers, such as those found in organic materials or biological light-harvesting complexes.
Krich and his colleagues believe their method is easy to implement for any spectroscopic research group. He highlights the team’s finding hidden structure in the well-known interaction of light with matter.
The study used the “transient absorption” method, with multiple laser powers and a newly-derived formula to systematically separate the effects from just one excitation from those from multiple excitations — up to six — in samples.
The scientists intend to expand the method and use it to analyze energy transport in new photovoltaic materials, which convert light energy into electrical energy.
The study, “Separating single- from multi-particle dynamics in nonlinear spectroscopy” is published in Nature.
P. Malý, J. Lüttig, P. A. Rose, A. Turkin, C. Lambert, J. J. Krich, and T. Brixner, Separating single- from multi-particle dynamics in nonlinear spectroscopy, Nature 616, 280–287 (2023). DOI: 10.1038/s41586-023-05846-7
SUNLAB Spin-off Enurgen Selected for Prestigious Accelerator
Congratulations to SUNLAB spin-off company Enurgen for being selected as one of 10 companies out of 600 applicants to participate in the Equinor & Techstars Accelerator in Oslo, Norway. Enurgen is a start-up born from the SUNLAB’s work in bifacial cell-to-system modelling. It is helping to bring about the global transition to a zero-carbon future by leveraging its advanced modelling software to help generate clean, renewable, sustainable energy to power today’s electric grids. The start-up is made up of former and current graduate students, researchers, and professors from the University of Ottawa.
The Enurgen team (from left to right): Elias Hussary, Chris Valdivia, Kibby Pollak, Ras-Jeevan Obhi, Henry Schriemer and Karin Hinzer