SUNLAB Welcomes Dr. Raphael St-Gelais for Its First NSERC CREATE TOP-SET Seminar

Wednesday, September 27, 2017, 3:30 p.m.Refreshments to be served starting at 3 p.mAdvanced Research Complex, room 233University of Ottawa, 25 Templeton StreetHeat transfer and energy conversion using near-field thermal radiationDr. Raphael St-Gelais, McGill UniversityABSTRACT: Thermal radiation between objects separated by sub-micron distances can overcome classical blackbody radiation by orders of magnitude, while being concentrated on a narrow frequency distribution. These unique characteristics could enable breakthrough energy conversion technologies. For example, modules in which a heat source evanescently radiates energy towards a specially tailored (i.e., low bandgap) photovoltaic cell are predicted to greatly outperform existing solid-state heat-to-electricity converters (e.g., thermoelectrics). I will review the physical principles behind heat transfer in this regime and discuss the exciting opportunity it allows for near-field thermophotovoltaic (NFTPV) electricity generation. I will present our recent work [1, 2] in which we used MEMS (micro-electromechanical systems) to achieve the first experimental demonstration of heat transfer in the regime required for NFTPV (i.e. sub-100 nm separation and large thermal gradient between parallel surfaces). I will also discuss the possibility of using hot-carrier internal photoemission effect to create silicon-based low-bandgap (0.5 eV) photovoltaic cells for NFTPV [3].[1] Raphael St-Gelais, Linxiao Zhu, Shanhui Fan, and Michal Lipson, “Near-field radiative heat transfer between parallel structures in the deep sub-wavelength regime” Nature Nanotechnology 11, pp. 515–519 (2016)[2] Raphael St-Gelais, Biswajeet Guha, Linxiao Zhu, Shanhui Fan, and Michal Lipson, “Demonstration of Strong Near-Field Radiative Heat Transfer between Integrated Nanostructures”, Nano Letters 14 (12), pp. 6971-6975 (2014)[3] Raphael St-Gelais, Gaurang. R. Bhatt, Linxiao Zhu, Shanhui Fan, and Michal Lipson, “Hot Carrier-Based Near-Field Thermophotovoltaic Energy Conversion,” ACS Nano 11, no. 3, pp. 3001–3009 (2017)BIO: Raphael St-Gelais will be joining the Department of Mechanical Engineering at the University of Ottawa in January 2018. His research program will focus on novel Opto-Thermo-Mechanical Microsystems for applications such as energy conversion, long wavelength photo-detection, and high precision force sensing. He is currently a postdoctoral researcher with Jack Sankey’s Optomechanics lab in McGill University, where he studies the interplay of mechanics and near-field thermal radiation in high-Q mechanical resonators. From 2013 to 2016 he was a postdoctoral researcher with Prof. Michal Lipson’s Nanophotonics Group at Cornell and Columbia Universities, where he worked on MEMS for near-field heat transfer control. He received the Alexander Graham Bell Canada Graduate Scholarship in 2009 for his Ph.D. work on Optical Sensors and MEMS-tunable optical components, as well as postdoctoral fellowships from FRQNT and NSERC for his work at Cornell & Columbia.NSERC CREATE Training in Optoelectronics for Power:from Science and Engineering to Technology (TOP-SET) is a training program to form a cohort of highly qualified personnel with comprehensive understanding of optoelectronic systems, capable of joining advanced R&D teams. For further details regarding TOP-SET, please contact Christine Couture, sunlabadmin@uottawa.caTOP-SET is funded in part by the Natural Sciences and Engineering Research Council of Canada.This seminar is funded by the University of Ottawa.