Title: Tuning Metal Halide Perovskite-Molecular Hybrids for Light Energy Conversion
Prashant V. Kamat is a Rev. John A. Zahm, C.S.C., Professor of Science in the Department of Chemistry and Biochemistry and Radiation Laboratory at the University of Notre Dame. He is also a Concurrent Professor in the Department of Chemical and Biomolecular Engineering. He earned his doctoral degree (1979) in Physical Chemistry from the Bombay University, and postdoctoral research at Boston University (1979-1981) and University of Texas at Austin (1981-1983). He joined Notre Dame in 1983. Professor Kamat has for nearly four decades worked to build bridges between physical chemistry and material science to develop advanced nanomaterials that promise cleaner and more efficient light energy conversion.
He has directed DOE funded solar photochemistry research for the past 40 years. In addition to large multidisciplinary interdepartmental and research center programs, he has actively worked with industry-sponsored research. He has served on many national panels on nanotechnology and energy conversion processes. He has published more than 500 scientific papers that have been well recognized by the scientific community (80000+ citations, h-index 142 –Source Web of Science). Thomson-Reuters has featured him as one of the most cited researchers each year during 2014-2022.
He is currently serving as the Editor-in-Chief of ACS Energy Letters. He has also served as the deputy editor of the Journal of Physical Chemistry Letters. He is a member of the advisory board of several scientific journals (Chemical Reviews, Journal of Colloid & Interface Science, ACS Applied Nanomaterials, Research on Chemical Intermediates, and Applied Electrochemistry). He was awarded Honda-Fujishima Lectureship award by the Japanese Photochemical Society (2006), CRSI medal by the Chemical Research Society of India (2011) Langmuir lectureship award (2013), Smalley Award by the Electrochemical Society (2022), Porter Medal in Photochemistry (2022) and Henry Storch Award in Energy Chemistry (2024 ACS National Award) . He is a Fellow of the Electrochemical Society (ECS), American Chemical Society (ACS), American Association for the Advancement of Science (AAAS), Materials Research Society (MRS), and Pravasi Fellow of the Indian National Science Academy.
Surface interaction of chromophore or redox active molecule which dictate the efficiency of energy/electron transfer, plays an important role in realizing photocatalytic and optoelectronic applications. Metal halide perovskite nanocrystals are interesting in the sense that they can either transfer energy or selectively transfer electrons or holes to the adsorbed molecules. The presentation will focus on two specific scenarios of the flow of energy and electron processes in CsPbBr3 nanocrystal-molecular hybrids. The energy transfer is probed through three molecular acceptors – rhodamine B (RhB), rhodamine isothiocyanate (RhB-NCS), and rose Bengal (RoseB), which contain an increasing degree of heavy atom pendant groups. When interacting with CsPbBr3 as an energy donor, photoluminescence excitation spectroscopy reveals that singlet energy transfer occurs with all three acceptors. However, the acceptor functionalization directly influences several key parameters that dictate the excited state interactions. Electron and/or hole transfer from excited CsPbBr3 nanocrystals to a molecular relay present near the interface offers another avenue to directly convert light energy into chemical energy. Such interfacial electron transfer of semiconductor nanocrystals has been widely explored in photocatalytic processes. The relative energy level alignment of donors and acceptors to direct the flow of charge carriers becomes important in dictating electron transfer. By employing viologen as a probe, we have elucidated the factors controlling the interfacial electron transfer processes. A basic understanding of the fundamental differences between the two excited deactivation processes (energy and charge transfer) and ways to modulate them should enable design of more efficient light harvesting assemblies with semiconductor and molecular systems.
References: 1. DuBose, J. T.; Kamat, P. V. Energy Versus Electron Transfer: Managing Excited-State Interactions in Perovskite Nanocrystal–Molecular Hybrids, Chemical Reviews 2022, 122, 12475–12494. 2. DuBose, J. T.; Kamat, P. V. Efficacy of Perovskite Photocatalysis: Challenges to Overcome, ACS Energy Letters 2022, 7, 1994-2011. 3. DuBose, J. T.; Kamat, P. V. Directing Energy Transfer in Halide Perovskite–Chromophore Hybrid Assemblies, Journal of the American Chemical Society 2021, 143, 19214–19223.
Keywords: energy conversion, semiconductors, photoinduced electron transfer
Host: Prof. Kyoung-Shin Choi