Presenter: Dr. zhuoying chen (ESPCI Paris/CNRS/Sorbonne Université)
Topic: Optoelectronic Applications of Colloidal and Hybrid Nanomaterials
Time: 14:00 pm, April 23rd (Tuesday)
Location: Conference Room B, BLDG 909
In this seminar, two topics on the optoelectronic applications of colloidal and hybrid nanomaterials will be presented: (1) The microscopic characterizations providing evidence on the upconversion-induced near-infrared light harvest in hybrid organo-lead halide perovskite solar cells. Photon upconversion represents a promising avenue to reduce the spectral mismatch losses limiting the efficiency of solar cells. Here the impact of inserting Yb3+/Er3+ co-doped KY7F22 upconversion nanoparticles (UCNPs) into the different interfaces of a solution-processed mixed-cation lead mixed-halide perovskite solar cell is studied in detail. (2) A new type of short-wave infrared (SWIR) photodetectors. Photodetection in the SWIR spectrum is a challenging task achieved often by costly low-bandgap compound semiconductors involving highly toxic elements. Here an alternative low-cost approach which relies on the plasmonic-induced photothermal effect of solution-processed colloidal gold nanorods (Au NRs). Hybrid device structures were fabricated by applying colloidal Au NRs on the surface of either a commercially available thermistor or a series of morphology-optimized resistive platinum (Pt) microwires. These hybrid Au-NRs/Pt photodetectors, capable to perform fast conversion between photon, heat, and resistance change, represents a brand-new strategy for alternative low-cost SWIR photodetection.
Dr. Z. Chen (HDR, Habilitation à diriger des recherches) has a multi-disciplinary scientific background and she is currently focusing on various research projects on the application of colloidal and hybrid organic-inorganic nanomaterials. During her PhD thesis at Columbia University (New York), she was trained as a material scientist focusing on colloidal synthesis and meta-material formation. She moved to the field of organic electronics for post-doctoral training and she studied charge transport and device physics in the Cavendish Laboratory of University of Cambridge. Since October 2010 Chen was recruited by the CNRS (National Scientific Research Center, France) through an open competition as a tenured research scientist. Since then she has been working on the optoelectronic applications of solution-processed colloidal nanocrystals and hybrid organic-inorganic systems. As the scientific leader, Chen has successfully carried out an ANR JCJC project on “Photovoltaic Devices based on Colloidal Nanocrystals as Light Harvesters” (2012-2015). Z. Chen is also a Marie-Curie fellow (Career integration grant) from 2013 to 2017. As the French-side scientific leader, she currently coordinates an ANR France-Germany project titled “Physics of degradation in organic, nanocrystal, and hybrid solar cells (PROCES)” from 2018.
Contact: Prof. Baoquan Sun