"Welcome to The Prashant Kamat lab at the University of Notre Dame! With the help of internal and external collaborations we have established a successful multidisciplinary research program in nanostructure architectures and energy conversion processes." - Prashant Kamat

Kamat Lab News

Wednesday, June 24, 2015Posted by Sebastian Snowberger


Summer 2015 Softball Game 1

After a grueling offseason full of chemistry, publishing and conferences, the Rad Lab Lab Rats shed their nitrile gloves and safety glasses for softball gloves and shades last night for the first game of the annual intramural softball season. The Lab Rats took on the formidable and reigning softball champs the Cap'n Crunch Cereal Killers. We got straight to work in the first inning with Kevin blasting our first home run of the night deep into right field going up by two runs. With bases loaded and butts out of seats, Joe took to home plate and cranked out yet another home run in the first for a grand slam putting the Lab Rats up 6-0. Our defense ran the field and held the Cereal Killers to just one run after some fancy acrobatics by our outfielders Steve and Mark. After all that excitement in the first, we kept quiet in the second inning and regrouped while holding the Cereal Killers to what would be their last run of the game. Top of the third saw our very own, Korean grown lefty allstar Joon take to home plate with Sooraj on base. While he may have been unsure which side of home plate to stand on or how to hold the bat, that didn't stop him from hitting a grounder to the infield and setting Ken up for our third homerun of the night putting the Lab Rats up 9-2. After we scored 4 more runs and had some fancy glove work by Maj-Britt at third base, the Cereal Killers admitted defeat after 5 innings giving the Lab Rats their second victory in franchise history at 13-2. We're happy to report that everyone in our batting line-up connected, even Tessa from Ireland confusing softball for Rounders, striking fear in the heart of all of our opponents. Come on out to the West Quad fields behind Hammes Bookstore next Tuesday at 6:30 as the Lab Rats take on Team EM!

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Monday, June 1, 2015Posted by Sebastian Snowberger

Multifaceted Excited State of CH3NH3PbI3. Charge Separation, Recombination, and Trapping

Read the latest paper from the Kamat Lab!

Multifaceted Excited State of CH3NH3PbI3. Charge Separation, Recombination, and Trapping

Multifaceted Excited State of CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>. Charge Separation, Recombination, and Trapping

Abstract: A need to understand the excited-state behavior of organic–inorganic hybrid perovskites, such as CH3NH3PbI3, has arisen due to the rapid development of perovskite solar cells. The photoinduced processes leading to the efficient charge separation observed in these materials remain somewhat elusive. This Perspective presents an overview of the initial attempts to characterize the excited-state and charge recombination dynamics in the prototypical material CH3NH3PbI3. While much has been accomplished in designing high-efficiency solar cells, the multifaceted nature of the CH3NH3PbI3 excited state offers ample challenges for the photovoltaic community to better comprehend. Building on this foundation may enable us to tackle the stability concerns that have shadowed the rise of perovskite solar cells. Furthermore, a better understanding of the excited-state properties can provide insight into the specific properties that have thrust this material to the forefront of photovoltaic research.

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Thursday, May 7, 2015Posted by Sebastian Snowberger

Synergistic Effects in the Coupling of Plasmon Resonance of Metal Nanoparticles with Excited Gold Clusters

Read the latest paper from the Kamat Lab!

Synergistic Effects in the Coupling of Plasmon Resonance of Metal Nanoparticles with Excited Gold Clusters

Synergistic Effects in the Coupling of Plasmon Resonance of Metal Nanoparticles with Excited Gold Clusters

Abstract: When molecules or clusters are within the proximity of metal particles, their electronic transitions can be drastically enhanced. We have now probed the off-resonance excitation of molecule-like, glutathione-capped gold clusters (Au-GSH) in the close proximity of larger (plasmonic) Au and Ag nanoparticles. The excited state absorption spectrum of Au-GSH* is obtained with monophotonic excitation. The characteristic absorption of Au-GSH* allows us to probe the influence of excited plasmonic nanoparticles coupled with the clusters. Although infrared (775 nm) lasers pulses do not produce Au-GSH*, the excited states of these clusters are formed when coupled with metal (Au, Ag) nanoparticles. Interestingly, the coupled excitation of Au-GSH/AgNP with 775 nm laser pulses also results in an enhanced field effect, as seen from increased plasmon response of the metal nanoparticles. Transient absorption measurements confirm the synergy between these two inherently different nanomaterials, causing them to display greater excitation features. Better understanding of metal cluster–metal nanoparticle interactions will have important implications in designing light harvesting systems, and optoelectronic devices.

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Thursday, April 23, 2015Posted by Sebastian Snowberger

Congratulations to Dr. Jeffrey Christians and Dr. Douglas Hines!

Congratulations to Dr. Jeffrey Christians and Dr. Douglas Hines!

Congratulations to graduate students Jeffrey Christians and Douglas Hines, who completed their Ph.D.s in Chemical and Biomolecular Engineering and Chemistry, respectively!

Jeff successfully defended his thesis entitled:

Mesostructured Thin Film Solar Cells: Examining Hole Transfer Mechanisms and Device Stability,

and was awarded the Eli J. and Helen Shaheen Graduate School Award in the Division of Engineering.

Doug successfully defended his thesis entitled:

Excited State Reactions at the Quantum Dot Surface,

and was awarded the Eli J. and Helen Shaeen Graduate School Award in the Division of Science.

Congratulations for completion of your Ph.D.s and having your excellent work recognized by the Graduate School!

Friday, February 27, 2015Posted by Sebastian Snowberger

Jeff Christians - National Renewable Energy Laboratory Postdoc

Graduate Student Jeff Christians gets postdoc at NREL

Join us in congratulating graduate student Jeffrey Christians who will be joining the National Renewable Energy Laboratory in Golden, CO (a suburb of Denver) as a postdoc with Dr. Joseph Luther! Jeff will be starting at NREL in May and will be working with Dr. Luther and others there to further develop and understand perovskite solar cells.

Friday, January 30, 2014Posted by Sebastian Snowberger

Humidity Effects on CH3NH3PbI3

Read the latest paper from the Kamat Lab!

Transformation of the Excited State and Photovoltaic Efficiency of CH3NH3PbI3 Perovskite upon Controlled Exposure to Humidified Air

Humidity Effects on CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>

Abstract: Humidity has been an important factor, in both negative and positive ways, in the development of perovskite solar cells, and will prove critical in the push to commercialize this exciting new photovoltaic technology. The interaction between CH3NH3PbI3 and H2O vapor is investigated by characterizing the ground state and excited state optical absorption properties, and probing morphology and crystal structure. These systematic undertakings elucidate the complex interaction inherent in this system, demonstrating that H2O exposure does not simply only CH3NH3PbI3 to revert to PbI2. It is shown that, in the dark, H2O is able to complex with the perovskite, forming a hydrate product similar to (CH3NH3)4PbI6•2H2O. This causes a decrease in absorption across the visible region of the spectrum and a distinct change in the crystal structure of the material. Femtosecond transient absorption spectroscopic measurements show the effect that humidity has on the ultrafast excited state dynamics of CH3NH3PbI3. More importantly, the deleterious effects of humidity on complete solar cells, specifically on photovoltaic efficiency and stability, are explored in light of these spectroscopic understandings.

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