MAE Seminar featuring Prof Tagliabue, “Nanoengineering of Light Absorption: from Hot Carrier Devices to Reconfigurable Metasurfaces”

ABSTRACT: In the last decade, optical nanoantennas have revolutionized light manipulation and control at the nanoscale. Light absorption was initially considered a purely detrimental process, reducing the efficiency of optoelectronic devices. Recently, however, it has attracted growing interest, enabling novel light-energy conversion pathways. In particular, two complementary opportunities are offered by light absorption in metallic (plasmonic) nanostructures and in dielectric nanoresonators for hot carrier generation and thermo-optical effects, respectively.

In this talk, I will first present fundamental aspects of plasmonic hot carrier generation and collection towards photoelectrochemical devices for light energy storage. In particular, I will report the construction, optoelectronic and photoelectrochemical characterization of plasmon-driven devices that operate via hot-hole injection, and I will compare them to their hot electron counterparts [1-4]. I will also show emerging opportunities for plasmonic hot carriers in redox-couple based photoelectrochemical devices and advanced optical design strategies for improving the efficiency [5]. I will next report on our recent effort towards the synthesis of record-high aspect ratio gold monocrystalline flakes [6] and I will discuss how we can leverage them for understanding fundamental electronic processes in metals as well as plasmonic photo-electrochemistry. Finally, I will focus on collective photothermal effects in plasmonic and dielectric nanoantennas. In particular, I will show how thermo-optical effects in resonant nanostructures can be leveraged to realize reconfigurable metasurfaces [7]. I will conclude with an outlook on applications of hot carriers and photothermal effects in nanoengineered optical antennas.

BIOSKETCH: Dr. Giulia Tagliabue is a Tenure-track Assistant Professor in the Department of Mechanical Engineering at EPFL. She joined the Engineering faculty in January 2019 and she is the head of the Laboratory of Nanoscience for Energy Technologies (LNET). She obtained her PhD in Mechanical Engineering from ETH Zurich in 2015. From 2015 to 2018 she was a Swiss National Science Foundation Fellow and she carried on her postdoctoral research jointly at Caltech and the Joint Center for Artificial Photosynthesis (JCAP). Dr. Tagliabue’s research focuses on the study of fundamental mechanisms and nanophotonic-design strategies for light-energy conversion devices, with a special interest for light-energy storage systems. Dr. Tagliabue is the recipient of the First Prize of the Rising Stars of Light Award 2020 and the same year she was also awarded an Eccellenza Grant from SNSF. She is member of the Material Research Society (MRS), the American Chemical Society (ACS) and the Optical Society of America (Optica)

Date(s) - Aug 18, 2022
1:00 pm - 2:00 pm

37-124 Engineering IV
420 Westwood Plaza Los Angeles CA