Research in the Grieco Lab
We are a physical chemistry group interested in applying time-resolved optical spectroscopy to solve problems in areas ranging from flexible bioelectronics to energy conversion and storage. Using a variety of ultrafast and steady-state spectroscopy methods, we aim to develop fundamental understandings of energy and charge transport in electronic materials. Our present goals include developing material design principles for accelerating the development of electrochemical devices that employ mixed ionic-electronic conduction.
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Mixed ionic-electronic conduction (MIEC) is a key electrochemical property underlying the operation of both organic electrochemical transistors in bioelectronic devices and energy storage in battery electrodes and supercapacitors. However, optimizing MIEC through material design is hindered by our lack of fundamental knowledge of mixed conduction. We are developing laser spectroscopy methods for probing of charge carriers in MIEC polymers in working electrochemical cells and devices to discover how to optimize their chemical and nano/mesoscale structures for improving device performance.
Asphaltene Nanoaggregate Photophysics
Asphaltene nanoaggregates, which constitute the high molecular weight component of crude oil, have intriguing optical properties, yet they are not viewed as useful, functional materials. We are investigating the photophysics of asphaltenes to learn about the fate and properties of excitations in these carbonaceous nanomaterials.
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Historically, time-resolved optical spectroscopy is used to study photoinitiated chemical reactions or physical processes that underlie energy conversion technologies, such as solar cells. However, many electronic and electrochemical/charge storage devices do not use light to operate, discouraging studies with optical spectroscopy. We are developing time-resolved spectroscopy methods for probing dynamics that are not initiated by light, and envision optical spectroscopy as a powerful tool for monitoring structure and charge transport in light-inactive materials. We further envision using ultrafast spectroscopy measurements to probe slow timescale dynamics, such as charge diffusion and storage. We propose that ultrafast snapshots of the system, taken on-the-fly, provide more detailed information about such slower processes integral to applications including electrochemical energy storage.
Funding
We thank the following organizations for funding our research
National Science Foundation
Spectroscopy Society of Pittsburgh
ACS Petroleum Research Fund