Article
Nanoscience & Nanotechnology
Yige Yao, Yunke Zhu, An Hu, Yunan Gao
Summary: This work reveals the rich in-plane exciton dynamics of CdSe/CdSeS CQW heterostructures, showing that at high temperatures, the in-plane charge carrier transfer dominates the exciton dynamics. As the temperature decreases, the internal processes of the exciton fine-structure begin to compete with the transfer process and eventually dominate the dynamics. The competition between these processes is quantitatively analyzed using a transfer-coupled three-state model, and the center-of-mass motion of excitons is experimentally resolved. This study provides new insight into exciton dynamics in CQWs and demonstrates their usefulness as a platform for studying exciton physics in various in-plane 2D semiconductor heterostructures.
Article
Chemistry, Physical
Caitlin R. McGranahan, David F. Watson
Summary: Carbodiimide-mediated coupling chemistry was used to synthesize heterostructures of CdSe and CdTe quantum dots with varying ratios of electron-donating CdTe QDs and electron-accepting CdSe QDs. The relative concentration of electron-accepting CdSe QDs within the mixtures greatly influenced the rate and efficiency of electron transfer.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Caitlin R. McGranahan, Guy E. Wolfe, Alejandro Falca, David F. Watson
Summary: The study utilized N,N'-dicyclohexylcarbodiimide (DCC) coupling chemistry to synthesize heterostructures of CdSe and CdTe quantum dots in colloidal dispersions, as well as immobilizing them on metal oxide thin films. The DCC-mediated formation of amide bonds between terminal carboxylic acid and amine groups of ligands on different QDs drove the formation of heterostructures, selectively yielding dispersed or immobilized structures with programmable compositions and energetic offsets. The results showed that the carbodiimide coupling chemistry can efficiently tether colloidal QDs selectively and covalently, enabling excited-state interfacial electron transfer.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Zachariah Hennighausen, Jisoo Moon, Kathleen M. McCreary, Connie H. Li, Olaf M. J. van 't Erve, Berend T. Jonker
Summary: The assembly of 2D materials in van der Waals heterostructures offers opportunities in materials design and synthesis. In this study, we report the formation of interlayer exciton-phonon bound states in Bi2Se3/WS2 heterostructures. These bound states appear as evenly separated peaks in the WS2 excitonic photoluminescence spectrum, corresponding to the energy of the A(1)((3)) surface phonon in Bi2Se3. Our work enhances understanding of interlayer van der Waals interactions and facilitates the development of technologies for spintronics, valleytronics, and quantum computing applications.
Article
Engineering, Electrical & Electronic
Ali Ciris, Bulent M. Basol, Yavuz Atasoy, Tayfur Kucukomeroglu, Abdullah Karaca, Murat Tomakin, Emin Bacaksiz
Summary: The interdiffusion between CdS-CdTe and CdSe-CdTe pairs was studied, showing that CdCl2 pretreatment can reduce the diffusion of S and Se into CdTe, thereby improving device performance.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Chemistry, Physical
Lifeng Wang, Dongmei Xiang, Kaimin Gao, Junhui Wang, Kaifeng Wu
Summary: Colloidal n-doped CdSe and CdSe/ZnS nanoplatelets have been achieved through a photochemical doping method, demonstrating successful additional electron doping at the conduction band edge. The key to successful doping lies in a high surface ligand coverage, while unpassivated surface cations may lead to depletion of the doped electrons.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Optics
Alexander M. Smirnov, Anastasiya D. Golinskaya, Bedil M. Saidzhonov, Roman B. Vasiliev, Vladimir N. Mantsevich, Vladimir S. Dneprovskii
Summary: The dynamics of resonantly excited excitons in CdSe/CdS nanoplatelets are determined by exciton-exciton interaction and phonon-induced cascade relaxation. The study also reveals the significance of exciton-exciton interaction in exciton dynamics, particularly in relation to the saturation of heavy-hole and light-hole exciton transitions. Additionally, the study experimentally investigates the lowest four band structure of CdSe/CdS nanoplatelets and the bleaching of higher energy transitions due to rapid cascade relaxation of electrons and holes.
JOURNAL OF LUMINESCENCE
(2021)
Article
Energy & Fuels
Darius Kuciauskas, Siming Li, John Moseley, David Albin, Chungho Lee, Arthur Louis Onno, Zachary Charles Holman
Summary: Cd(Se)Te solar cells have potential for increasing voltage, with voltage losses mainly attributed to nonradiative recombination quantified by carrier lifetime and radiative efficiency. The majority of voltage losses are found to be due to recombination in the absorber bulk, with front interface recombination having a larger impact within the first few nanoseconds after excitation. Time-resolved photoluminescence experiments can be used to assess the relative contributions of different recombination rates.
IEEE JOURNAL OF PHOTOVOLTAICS
(2022)
Article
Chemistry, Multidisciplinary
Igor Fedin, Mateusz Goryca, Dan Liu, Sergei Tretiak, Victor Klimov, Scott A. Crooker
Summary: Studies have shown that colloidal CdSe quantum dots with a high degree of asymmetric internal strain exhibit desirable optical properties and have the potential for emitting single indistinguishable photons.
Article
Chemistry, Multidisciplinary
Hoang Long Nguyen, Thanh Nhut Do, Emek G. Durmusoglu, Merve Izmir, Ritabrata Sarkar, Sougata Pal, Oleg V. Prezhdo, Hilmi Volkan Demir, Howe-Siang Tan
Summary: In this study, the ultrafast spectral diffusion, vibronic dynamics, and energy relaxation of CdSe colloidal quantum wells (CQWs) at room temperature were measured using two-dimensional electronic spectroscopy (2DES). The energy relaxation from light-hole (LH) excitons to heavy-hole (HH) excitons was observed to occur within a time scale of approximately 210 fs. Equilibration dynamics between the spectroscopically accessible HH excitonic state and a dark state were found to take place within a time scale of approximately 160 fs. The spectral diffusion dynamics in HH excitons were analyzed using center line slope analysis, revealing a sub-200 fs decay and oscillatory features resolved at 4 and 25 meV. Quantum calculations were performed to replicate and explain the observed dynamics. The 4 meV mode was found to be in the near-critically damped regime and may mediate the transition between the bright and dark HH excitons. These findings demonstrate the capability of 2DES to comprehensively and detailedly characterize the ultrafast spectral properties in CQWs and similar nanomaterials.
Review
Physics, Applied
Hao Liu, Yixin Zong, Pan Wang, Hongyu Wen, Haibin Wu, Jianbai Xia, Zhongming Wei
Summary: Excitons in van der Waals heterostructures exhibit multiple excellent characteristics, including Bose-Einstein condensate state, moire excitons, and complex exciton dynamics. The applications of excitons in valley devices have a promising outlook, but there are still some existing problems that need to be addressed.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Alexander M. Smirnov, Anastasia D. Golinskaya, Vladimir N. Mantsevich, Maria Kozlova, Kseniia V. Ezhova, Bedil M. Saidzhonov, Roman B. Vasiliev, Vladimir S. Dneprovskii
Summary: Experimental investigations were conducted on the transient absorption of colloidal heterostructured CdSe/CdS nanoplatelets under high-intensity nanosecond laser pulses, revealing a strong dependence on nanoplatelets concentration and pump intensities. Nonlinear transmission changes in nanoplatelets solutions were explained by various factors, and the identification of conditions for optical gain in colloidal solutions was a significant result.
RESULTS IN PHYSICS
(2022)
Article
Chemistry, Physical
Dongmei Xiang, Yulu Li, Lifeng Wang, Tao Ding, Junhui Wang, Kaifeng Wu
Summary: In this study, the electron and hole spin dynamics in CdSe colloidal nanoplatelets of varying thicknesses were investigated using circularly polarized transient absorption spectroscopy. The results showed that hole spin-flip occurred within 200 fs, while the electron spin lifetime decreased as the platelet thickness was reduced. The findings suggest an exchange interaction between the electron and the hole, and/or surface dangling bond spins enhanced by quantum confinement.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Multidisciplinary Sciences
Philipp Merkl, Chaw-Keong Yong, Marlene Liebich, Isabella Hofmeister, Gunnar Berghaeuser, Ermin Malic, Rupert Huber
Summary: The authors demonstrate proximity-controlled strong-coupling between Coulomb correlations and lattice dynamics in neighboring van der Waals materials (WSe2 and a gypsum layer), creating electrically neutral hybrid exciton-phonon eigenmodes called excitonic Lyman polarons. This approach provides a promising new strategy to engineer novel ground states of two-dimensional systems by controlling the spatial wavefunction overlap of excitons and phonons.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
X. R. Hou, S. D. Wang
Summary: In this study, the quasiparticle band structures and excitonic optical properties of SiC/MoSSe heterostructures were investigated using the GW + Bethe-Salpeter equation approach. The results show that all four stable structures of SiC/MoSSe heterostructures are favorable for producing high binding energy interlayer excitons. The modulation of optical dipole oscillator strength and radiative lifetimes is significant due to the different intrinsic dipole moments of MoSSe.
APPLIED SURFACE SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Lauren N. McHugh, Michael F. Thorne, Georgina Robertson, Giorgio Divitini, Thomas D. Bennett
Summary: The research investigates the formation and properties of single-component metal-organic framework crystal-glass composites (MOF-CGCs), producing materials with chemically identical glassy and crystalline phases. X-ray diffraction shows the presence of the crystalline phase even after heating, and interfacial compatibility between the phases was explored. The CO2 adsorption measurements indicate that the MOF-CGCs have uptake levels between those of the crystalline and glassy phases.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Materials Science, Multidisciplinary
Felix Utama Kosasih, Francesco Di Giacomo, Jordi Ferrer Orri, Kexue Li, Elizabeth M. Tennyson, Weiwei Li, Fabio Matteocci, Gunnar Kusch, Narges Yaghoobi Nia, Rachel A. Oliver, Judith L. MacManus-Driscoll, Katie L. Moore, Samuel D. Stranks, Aldo Di Carlo, Giorgio Divitini, Caterina Ducati
Summary: This study demonstrates that Na diffusion occurs in the fabrication process of perovskite solar modules, forming Na-Br-rich perovskite and enhancing its luminescence. However, the continuous diffusion of Na throughout the module's lifetime, especially under the electric field and elevated temperatures during device operation, may have long-lasting effects on the module's performance.
ENERGY & ENVIRONMENTAL MATERIALS
(2023)
Article
Chemistry, Physical
Danila Quarta, Stefano Toso, Gabriele Saleh, Rocco Caliandro, Anna Moliterni, Andrea Griesi, Giorgio Divitini, Ivan Infante, Giuseppe Gigli, Cinzia Giannini, Liberato Manna, Carlo Giansante
Summary: We have developed a colloidal synthesis method for bismuth chalcohalide nanocrystals with a hexagonal phase. The structure of these nanocrystals can be described by the Bi13S18X2 (where X = Br and I) model. It was found that the presence of Bi24+ dimers, formed by columns of Bi atoms, and Peierls-type distortions are responsible for the anomalously low band gap and intervalence charge transfer in this material. Our findings and synthetic approach provide fundamental understanding for the use of hexagonal bismuth chalcohalides in diverse applications such as photocatalysis and thermoelectrics.
CHEMISTRY OF MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Sneha Kagatikar, Dhanya Sunil, Dhananjaya Kekuda, M. N. Satyanarayana, Suresh D. Kulkarni, Y. N. Sudhakar, Anoop Kishore Vatti, Aditya Sadhanala
Summary: This study focuses on the properties of two pyrene-based chalcones and explores their potential applications in semiconductors and electrooptical devices.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Nanoscience & Nanotechnology
Kun Sun, Renjun Guo, Yuxin Liang, Julian E. Heger, Shangpu Liu, Shanshan Yin, Manuel A. Reus, Lukas V. Spanier, Felix Deschler, Sigrid Bernstorff, Peter Mueller-Buschbaum
Summary: In this study, the operational stability of perovskite solar cells (PSCs) was investigated, and it was found that the absorption of water caused volume expansion within the perovskite grains, leading to the degradation of the cells and a decrease in their performance. It was also observed that modifying the buried interface of the PSCs can slow down the degradation.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Sarah R. E. Orsborne, Jeffrey Gorman, Leah R. Weiss, Akshay Sridhar, Naitik A. Panjwani, Giorgio Divitini, Peter Budden, David Palecek, Sean T. J. Ryan, Akshay Rao, Rosana Collepardo-Guevara, Afaf H. El-Sagheer, Tom Brown, Jan Behrends, Richard H. Friend, Florian Auras
Summary: In this study, DNA-encoded assembly of pentacenes capable of singlet fission (SF) was used to achieve precise structural control and explore the SF process. The results showed that SF evolved through a quintet state and demonstrated efficient and controlled semiconductor operation.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Damien Degoulange, Raj Pandya, Michael Deschamps, Dhyllan A. Skiba, Betar M. Gallant, Sylvain Gigan, Hilton B. de Aguiar, Alexis Grimaud
Summary: High-resolution Raman imaging is used to investigate the interface of salt-salt aqueous biphasic systems (ABSs) at a molecular level, revealing a gradual change of environment instead of a sharp molecular interface. This knowledge is of great importance in understanding aqueous interfaces and has significant implications in various biological and technological settings, including novel battery technologies.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Multidisciplinary Sciences
Robert A. Jagt, Ivona Bravic, Lissa Eyre, Krzysztof Galkowski, Joanna Borowiec, Kavya Reddy Dudipala, Michal Baranowski, Mateusz Dyksik, Tim W. J. Van de Goor, Theo Kreouzis, Ming Xiao, Adrian Bevan, Paulina Plochocka, Samuel D. Stranks, Felix Deschler, Bartomeu Monserrat, Judith L. MacManus-Driscoll, Robert L. Z. Hoye
Summary: The complex coupling between charge-carriers and phonons in bismuth oxyiodide (BiOI) is studied, revealing its effectiveness for X-ray detection.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Physical
Michael L. Crawford, James C. Sadighian, Yasser Hassan, Aditya Sadhanala, Laila Nawab, Cathy Y. Wong
Summary: This study tracks the excited-state dynamics during photoinduced halide segregation using transient absorption spectroscopy. The experimental results show that the Auger recombination dynamics accelerate and electron-hole overlap enhances as the bandgap narrows. The simulation results support a segregation mechanism where the halides form a domain within the nanocrystals.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Feng Fei Zhang, Eva Aw, Alexander G. Eaton, Rebecca R. C. Shutt, Juhwan Lim, Jung Ho Kim, Thomas J. Macdonald, Cesar I. I. I. D. L. Reyes, Arjun Ashoka, Raj Pandya, Oliver D. Payton, Loren Picco, Caroline E. Knapp, Furio Cora, Akshay Rao, Christopher A. Howard, Adam J. Clancy
Summary: By ionically etching and dissolving, arsenic-phosphorus alloy nanoribbons (AsPNRs) have been created with small band gap, high electrical conductivity, and high hole mobilities. These properties make AsPNRs suitable for electronic devices such as near-infrared detectors, quantum computing, and solar cells.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Raj Pandya, Angus Mathieson, Buddha Deka Boruah, Hilton B. de Aguiar, Michael de Volder
Summary: Photobatteries, which capture and store solar energy in a single device, utilize light-induced charging to drive lithiation changes in electrodes. The mechanism of operation, involving both faradaic and nonfaradaic effects, remains poorly understood.
Article
Nanoscience & Nanotechnology
Raj Pandya, Lorenzo Valzania, Florian Dorchies, Fei Xia, Jeffrey Mc Hugh, Angus Mathieson, Hwee Jien Tan, Thomas G. Parton, Louis Godeffroy, Katrina Mazloomian, Thomas S. Miller, Frederic Kanoufi, Michael De Volder, Jean-Marie Tarascon, Sylvain Gigan, Hilton B. de Aguiar, Alexis Grimaud
Summary: Confocal optical microscopy is successfully applied to visualize the dynamics of solid and liquid electrolyte in operating batteries. By examining important cathode materials, the study reveals the transport velocity of Li-phase fronts and volume changes, as well as heterogeneities in the electrodes and electrolyte. It is discovered that surface-limited reactions and competing rates within agglomerate particles control the (de)lithiation process.
NATURE NANOTECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Anna Stadlbauer, Lissa Eyre, Alexander Biewald, Felix Rauh, Markus W. Heindl, Shangpu Liu, Jonathan Zerhoch, Sascha Feldmann, Achim Hartschuh, Felix Deschler
Summary: The electronic states and exciton binding energies of layered Ruddlesden-Popper (RP) metal-halide perovskites can be tailored through changes of their chemical composition. This study reports an unexpected excitation energy dependence of photoexcitation relaxation dynamics in mixed-dimensional RP perovskite thin films, resulting in spectrally broadband luminescence. These findings hold potential for the development of broadband white-light emitters and other light-emitting devices.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Vladimir Lomonosov, Thomas M. R. Wayman, Elizabeth R. Hopper, Yurii P. Ivanov, Giorgio Divitini, Emilie Ringe
Summary: Bimetallic Pd-Mg nanoparticles were synthesized and studied for their catalytic and photocatalytic properties in selective hydrogenation of acetylene. The Mg-Pd structures consist of metallic Mg and sustain plasmon resonances. Even without light excitation, the Pd-Mg nanostructures exhibit excellent catalytic activity. With laser excitation, the reaction rate increases and the activation energy decreases, indicating a catalytic behavior affected by plasmon excitation. The coupling between Mg's plasmonic and Pd's catalytic properties paves the way for sustainable catalytic structures for selective hydrogenation processes.
Article
Chemistry, Multidisciplinary
Angus G. M. Mathieson, Wesley M. Dose, Hans-Georg Steinrueck, Christopher J. Takacs, Sascha Feldmann, Raj Pandya, Alice J. Merryweather, David Mackanic, Akshay Rao, Felix Deschler, Michael De Volder
Summary: In this study, we achieve controlled doping of halide perovskites with lithium ions using solid state lithium-ion battery inspired devices. We analyze the material through a range of operando techniques and identify three doping regimes, with corresponding decomposition products. By combining different measurement methods, we separate the effects of free charge carriers and intercalated lithium and provide a quantitative framework for the design of doped-perovskite energy devices.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
