Strong Light-Matter Interactions in Low-Dimensional Excitonic Semiconductors
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Date: Fri, August 28, 2026
Time: 1:30pm - 2:30pm
Location: Holmes Hall 389; online available, contact ECE Office for details
Speaker: Dr. Deep Jariwala, University of Pennsylvania
Abstract:
The isolation of stable atomically thin two-dimensional (2D) materials on arbitrary substrates has led to a revolution in solid state physics and semiconductor device research over the past decade. A variety of other 2D materials (including semiconductors) with varying properties have been isolated raising the prospects for devices assembled by van der Waals forces. Particularly, these van der Waals bonded semiconductors exhibit strong excitonic resonances and large optical dielectric constants as compared to bulk 3D semiconductors. First, I will focus on strong light-matter coupling in excitonic 2D semiconductors, namely chalcogenides of Mo and W. Visible spectrum band-gaps with strong excitonic absorption makes transition metal dichalcogenides (TMDCs) of molybdenum and tungsten as attractive candidates for investigating strong light-matter interaction formation of hybrid states. We will present our recent work on the light trapping in multi-layer TMDCs when coupled to reflective substrates. Next, I will show the extension of these results to superlattices of excitonic chalcogenides, multilayer halide perovskites as well as metal organic chalcogenolates. These hybrid multilayers and materials offer a unique opportunity to tailor the light-dispersion in the strong to ultra-strong coupling regime. I will extend these concepts to wide-band-gap metal organic chalcogenolates and ultra-wide band gap hexagonal boron nitride in which we have found some of the strongest and most anisotropic excitons to date. Wherever opportunity permits, I will discuss the physics of strong light-matter coupling and its applications in practical devices such as phase modulators, photovoltaics as well as light emitting devices. Finally, if time permits, I extend some of these concepts to 1D carbon-nanotubes. Our results highlight the vast opportunities available to tailor light-matter interactions and building practical devices with 2D and 1D semiconductors.Biography:
Deep Jariwala is an Associate Professor and the Peter & Susanne Armstrong Distinguished Scholar in
the Electrical and Systems Engineering as well as Materials Science and
Engineering at the University of Pennsylvania (Penn). Deep completed
his undergraduate degree in Metallurgical Engineering from the Indian
Institute of Technology in Varanasi and his Ph.D. in Materials Science
and Engineering at Northwestern University. Deep was a Resnick Prize
Postdoctoral Fellow at Caltech before joining Penn to start his own
research group. His research interests broadly lie at the intersection
of new materials, surface science and solid-state devices for computing,
opto-electronics and energy harvesting applications in addition to the
development of correlated and functional imaging techniques. Deep’s
research has been widely recognized with several awards from
professional societies, funding bodies, industries as well as private
foundations, the most notable ones being the Optica Adolph Lomb Medal,
the Bell Labs Prize, the AVS Peter Mark Memorial Award, IEEE
Photonics Society Young Investigator Award, IEEE Nanotechnology Council
Young Investigator Award, IUPAP Early Career Scientist Prize in
Semiconductors, the SPIE Early career achievement award and the Alfred P. Sloan Fellowship. He
has published over 150 journal papers with more than 25000 citations
and holds several patents. He serves as the Associate Editor for Nano Letters (ACS) and has been appointed as a Distinguished
Lecturer for the IEEE Nanotechnology Council for 2025 as well as Fellow
of Optica (2026) and SPIE (2027). He is the co-founder of Agni
Semiconductor, a start-up company aiming to commercialize ferrodiode
memory technology. In 2027, Deep will join as the Governor’s Chair
professor at University of Tennessee Knoxville and the Oak Ridge
National Laboratory.
