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CATEGORIES:Lectures & Presentations
DESCRIPTION:The NQPI Seminar Series\n\nfeatures Mariama Rebello Sousa Dias
of the Department of Physics at the University of Richmond discusses Advanc
ements in the Design of Optical Components for Efficient Optoelectronic Dev
ices Operating at High Temperature on April 27 at 4:10 p.m. in Clippinger 1
94.\n\n \n\nAbstract: Using nanostructures with different chemical composit
ions and geometry is a promising way to improve the performance of optical
sensors\, energy harvesting devices\, and photocatalysts. However\, photoni
c materials for high-temperature applications must withstand their temperat
ure operation while keeping their function. In the first part of this talk\
, I will highlight recent progress in using alloys with different chemical
compositions as a pathway to control and tune their optical response. To de
termine the ideal composition for a particular application\, we use a combi
nation of traditional material synthesis and characterization methods\, sim
ulation\, and modeling methods. In particular\, Au-Al has shown to be promi
sing for sensor applications operating at high temperatures. Here\, we desi
gned an artificial neural network trained to predict an Al-Au system's diel
ectric response. To confirm our prediction\, we fabricated bimetallic films
with different compositions and measured their optical response at differe
nt temperatures. We find that the accuracy of the ML is very high\, and the
time response is relatively short. Moreover\, we show that all alloys outp
erform their pure counterparts in sensitivity\, with Au0.85Al0.15 being th
e best candidate for replacing pure gold in sensors based on the surface pl
asmon resonance effect. This approach can expand optical properties databas
es of known and hypothetical systems.\n\n \n\nIn the second part\, I will r
eport the recent advancements in emitter design for thermophotovoltaics (TP
Vs). In thermophotovoltaics\, heat from a thermal emitter is directly conve
rted to electricity via a photovoltaic (PV) cell. One way to decrease syste
m losses is to tailor the emitted spectrum to a specific PV cell. In this w
ork\, we propose to use a thin film configuration for the emitter. We defin
e a figure of merit (FOM) as the ratio of the power generated by the photov
oltaic cell () and the power emitted by the emitter (). We analyze the opti
mal configuration of >2000 emitters that can operate at temperatures above
2000 ºC. The methods implemented here apply to any PV cell. Thus\, we evalu
ate the best emitter candidates for Si\, Ge\, GaSb\, InGaAs\, and InGaAsSb
cells. Due to the ultra-high temperature operation of the thermophotovoltai
c\, the thermal stability and the mismatch in the thermal expansion coeffic
ient of each material combination are discussed. Our results show that FOMs
above 50% are achievable under ideal conditions. This work can shed light
on high-temperature photonics\, where a simple emitter design can result in
higher efficient photoelectronic devices.\n\n \n\nBrief Bio: Mariama R. S
. Dias is an Assistant Professor at the University of Richmond. She receive
d her Ph.D. in Physics from The Federal University of Sao Carlos\, Brazil\,
in 2014. During her Ph.D.\, she held visiting research appointments at the
Ohio University\, The Free University of Berlin\, and The University of Wu
erzburg. Before arriving at UR\, she was a postdoctoral researcher at the U
niversity of Maryland\, holding the Schlumberger Faculty for the Future Fel
lowship. Dr. Dias’ lab currently researches topics that focus on metallic\,
oxide\, and semiconductor nanostructures with potential applications in op
tics\, plasmonics\, nanoelectronics\, and energy harvesting devices.
DTEND:20230427T211500Z
DTSTAMP:20241124T002735Z
DTSTART:20230427T201000Z
GEO:39.322604;-82.099286
LOCATION:Clippinger Laboratories\, 194
SEQUENCE:0
SUMMARY:NQPI Seminar | Advancements in the Design of Optical Components for
Efficient Optoelectronic Devices Operating at High Temperature\, April 27
UID:tag:localist.com\,2008:EventInstance_42348297050754
URL:https://calendar.ohio.edu/event/nqpi_seminar_series_5572
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