Article
Chemistry, Multidisciplinary
Taehee Kim, Yu-Ho Won, Eunjoo Jang, Dongho Kim
Summary: The study reveals that the Auger recombination processes of InP/ZnSe/ZnS quantum dots are influenced by the midshell structures, ultimately affecting the performance of QD-LEDs. The midshell thickness impacts the exciton-exciton binding energy and the negative trion Auger recombination behavior.
Article
Chemistry, Multidisciplinary
Chun Zhou, Joao M. Pina, Tong Zhu, Darshan H. Parmar, Hao Chang, Jie Yu, Fanglong Yuan, Golam Bappi, Yi Hou, Xiaopeng Zheng, Jehad Abed, Hao Chen, Jian Zhang, Yuan Gao, Bin Chen, Ya-Kun Wang, Haijie Chen, Tianju Zhang, Sjoerd Hoogland, Makhsud Saidaminov, Liaoxin Sun, Osman M. Bakr, Hongxing Dong, Long Zhang, Edward H. Sargent
Summary: In this study, Perovskite quantum dots superlattices were successfully self-assembled with the assistance of sodium as assembly director, forming ordered three-dimensional structures with increased attraction and decreased inter-dot distance. These structures facilitate exciton delocalization and sustained nanosecond lasing operation with a threshold of 25 mu J cm(-2).
Article
Chemistry, Physical
Haochen Sun, Paul Cavanaugh, Ilan Jen-La Plante, Christian Ippen, Maria Bautista, Ruiqing Ma, David F. Kelley
Summary: Transient absorption and time-resolved photoluminescence spectroscopies were used to study the hole tunneling and Auger dynamics in high-quality InP/ZnSe/ZnS quantum dots. The study revealed that trapped holes can tunnel into the valence band, converting one type of biexciton to another type.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Nima Taghipour, Mariona Dalmases, Guy L. Whitworth, Miguel Dosil, Andreas Othonos, Sotirios Christodoulou, Shanti Maria Liga, Gerasimos Konstantatos
Summary: This study utilizes PbS/PbSSe core/alloyed-shell colloidal quantum dots (CQDs) as a gain medium for infrared laser devices. The researchers achieved highly suppressed Auger recombination and lower amplified spontaneous emission (ASE) threshold by doping these engineered CQDs and successfully achieved near-infrared laser emission.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Physical
Jayanta Dana, Tufan Ghosh, Itay Gdor, Arthur Shapiro, Efrat Lifshitz, Sanford Ruhman
Summary: The spectator exciton method is used to study the influence of the number of excitons on the absorption of nanocrystals by comparing their absorption spectra. The experiments show that in CdSe nanodots, conflicts in electron spin orientation result in the blocking of 50% of hot electrons from directly cooling to the band edge. In contrast, loading of cold excitons in PbS nanodots leads to a gradual broadening of the 1Se1Sh absorption band, indicating the inadequacy of using a single probe wavelength to measure the filling of band-edge states. Furthermore, the sub band gap induced absorption characteristic of hot exciton states in all quantum dots is not the low-energy half of biexciton shifting to the 1Se1Sh absorption band, but rather part of a broad induced absorption characteristic of hot excitons regardless of the spectator count. Finally, the unique capability of spectator excitons (SXs) to detect contributions of stimulated emission to pump-probe signals is demonstrated in singly excited PbS nanocrystals, where no such contributions are observed.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Andre Maier, Fabian Strauss, Pia Kohlschreiber, Christine Schedel, Kai Braun, Marcus Scheele
Summary: The intrinsic response time and bandwidth of lead sulfide nanocrystal photodetectors were investigated using a two-pulse coincidence photoresponse technique. The results indicated an intrinsic response time of approximately 1 ns and an intrinsic bandwidth of approximately 0.55 GHz. Auger recombination assisted by nanocrystal surface defects was identified as the dominant mechanism. The intrinsic response time could be further tuned by controlling ligand coverage and trap states.
Article
Materials Science, Multidisciplinary
Alexander Steinhoff, Frank Jahnke, Matthias Florian
Summary: A novel many-body theory of EEA based on first-principle band structures and Coulomb interaction matrix elements is presented, going beyond an effective bosonic picture. Applying the theory to monolayer MoS2 encapsulated in hexagonal BN, an EEA coefficient of the order of 10(-3) cm(2) s(-1) at room temperature is obtained, indicating that carrier losses are often dominated by other processes like defect-assisted scattering. The study provides a perspective to quantify the efficiency of intrinsic EEA processes in various 2D materials in modern materials research.
Article
Chemistry, Multidisciplinary
Nima Taghipour, Guy L. Whitworth, Andreas Othonos, Mariona Dalmases, Santanu Pradhan, Yongjie Wang, Gaurav Kumar, Gerasimos Konstantatos
Summary: A binary blend of CQDs and ZnO nanocrystals is used to passivate trap states in PbS-CQD gain medium, leading to improved Auger lifetime and suppression of trap-assisted Auger recombination. Integration of this binary blend with a DFB resonator has demonstrated stable single-mode lasing emission with low threshold and continuous operation of 5 hours under room temperature and ambient conditions.
ADVANCED MATERIALS
(2022)
Article
Physics, Multidisciplinary
P. Henzler, C. Traum, M. Holtkemper, D. Nabben, M. Erbe, D. E. Reiter, T. Kuhn, S. Mahapatra, K. Brunner, D. Seletskiy, A. Leitenstorfer
Summary: The study examines ultrafast transmission changes around the fundamental trion resonance in a negatively charged II-VI quantum dot after exciting a p-shell exciton. The biexcitonic induced absorption reveals quantum beats between hot-trion states at 133 GHz. The relaxation of the P-shell hole within 390 fs dominates interband dephasing, while trionic coherence remains stored in the spin system for 85 ps due to Pauli blocking of the triplet electron.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Samuel G. Carter, Stefan C. Badescu, Allan S. Bracker, Michael K. Yakes, Kha X. Tran, Joel Q. Grim, Daniel Gammon
Summary: By utilizing a trion with one hole in an excited orbital, the strong spin-orbit interaction in quantum dots allows for optical spin rotations and cycling transitions, addressing the compatibility issue for quantum information applications. The specific trion triplet forms a double Lambda system even in a Faraday magnetic field, enabling fast hole spin initialization and coherent population trapping. Furthermore, the lowest trion transitions still effectively preserve spin, allowing for fast optical spin control combined with cycling transitions for spin readout.
PHYSICAL REVIEW LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Kwang Jin Lee, Gahyeon Kim, Joonhyung Lim, Sanghee Nah, Kwang Seob Jeong, Minhaeng Cho
Summary: Controlling the transition dipole moment is crucial for various photophysical characteristics in semiconductors, especially in suppressing Auger recombination in quantum dots (QDs) for the development of novel applications. Introducing nanocomposite materials successfully controlled the biexciton Auger recombination process in nanocrystal thin-film, leading to a significant reduction in BAR rate. This modulation of the net transition dipole moment provides insight into rational design of QDs combined with nanostructures for efficient suppression of Auger recombination rates.
ADVANCED OPTICAL MATERIALS
(2022)
Review
Chemistry, Multidisciplinary
Namyoung Ahn, Cleiment Livache, Valerio Pinchetti, Victor I. Klimov
Summary: Lasers and optical amplifiers based on solution-processable materials, including colloidal quantum dots, have been highly sought-after for their compatibility, scalability, and ease of integration. Recent advances in colloidal nanocrystal lasing devices have shown promising progress towards the development of viable devices.
Review
Materials Science, Multidisciplinary
Qilin Yuan, Ting Wang, Panlong Yu, Hanzhuang Zhang, Han Zhang, Wenyu Ji
Summary: This article reviews the electroluminescence properties and fabrication/characterization technologies of Quantum-dot light-emitting diodes (QLEDs), emphasizing the significance of dynamic processes of charge carriers and related characterization technology. Strategies to improve device performance through interface modification and QD design are summarized, along with the corresponding physics and chemistry mechanisms.
ORGANIC ELECTRONICS
(2021)
Article
Chemistry, Physical
Ayendrila Das, Krishna Mishra, Subhadip Ghosh
Summary: This study investigates the blinking of freely diffusing CsPbBr3 nanocrystals using fluorescence lifetime correlation spectroscopy. The results show that, at low excitation power, the microsecond blinking timescale of the exciton state matches well with that of the trap state, and both timescales correlate with the growth timescale. On the other hand, high excitation power leads to more dispersive blinking due to enhanced sample heterogeneity.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Physics, Applied
A. Kamboj, L. Nordin, P. Petluru, A. J. Muhowski, D. N. Woolf, D. Wasserman
Summary: This study demonstrates all-epitaxial guided-mode resonance mid-wave infrared type-II superlattice nBn photodetectors, showing polarization- and angle-dependent detector response with strongly enhanced absorption. The detectors exhibit high operating temperature external quantum efficiencies over 50% at 200K for TE-polarized light with a thin absorber layer. The calculated specific detectivity on resonance at T = 200K is comparable with state-of-the-art MWIR detectors.
APPLIED PHYSICS LETTERS
(2021)
Article
Chemistry, Physical
Jessica Q. Geisenhoff, Ashley K. Tamura, Alina M. Schimpf
CHEMISTRY OF MATERIALS
(2020)
Article
Chemistry, Inorganic & Nuclear
Maximilian G. Bernbeck, Jeremy D. Hilgar, Jeffrey D. Rinehart
Article
Chemistry, Multidisciplinary
Linfeng Chen, Michael J. Turo, Milan Gembicky, Ruth A. Reinicke, Alina M. Schimpf
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2020)
Article
Chemistry, Physical
Wei Cao, Alex J. Mantanona, Haochuan Mao, Naneki C. McCallum, Yang Jiao, Claudia Battistella, Valeria Caponetti, Nanzhi Zang, Matthew P. Thompson, Marco Montalti, J. Fraser Stoddart, Michael R. Wasielewski, Jeffrey D. Rinehart, Nathan C. Gianneschi
CHEMISTRY OF MATERIALS
(2020)
Article
Chemistry, Physical
Alexander G. Rachkov, Alina M. Schimpf
Summary: A one-pot colloidal synthesis method for Cu3-xP nanoplatelets is presented, allowing control over the size and LSPR energy of the nanocrystals while maintaining low polydispersity. This method provides a platform for systematic investigation of the chemical processes involved in Cu3-xP nanocrystal formation.
CHEMISTRY OF MATERIALS
(2021)
Review
Chemistry, Multidisciplinary
Wei Cao, Xuhao Zhou, Naneki C. McCallum, Ziying Hu, Qing Zhe Ni, Utkarsh Kapoor, Christian M. Heil, Kristine S. Cay, Tara Zand, Alex J. Mantanona, Arthi Jayaraman, Ali Dhinojwala, Dimitri D. Deheyn, Matthew D. Shawkey, Michael D. Burkart, Jeffrey D. Rinehart, Nathan C. Gianneschi
Summary: Melanin is a natural biomaterial with various functions found in living organisms, classified into different types based on chemical precursors. Despite its complexity and diversity in chemical structure, synthetic mimics have been used to study its structure-function relationships. Efforts are being made to elucidate biosynthetic pathways and characterize melanin materials for potential new opportunities in synthetic materials.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Maxime Tricoire, Luca Muenzfeld, Jules Moutet, Nolwenn Mahieu, Leo La Droitte, Eufemio Moreno-Pineda, Frederic Gendron, Jeremy D. Hilgar, Jeffrey D. Rinehart, Mario Ruben, Boris Le Guennic, Olivier Cador, Peter W. Roesky, Gregory Nocton
Summary: A series of lanthanide sandwich complexes ligated by cyclononatetraenyl and cyclooctatetraenyl ligands were reported, showing different coordination patterns in the solid state depending on the size of the corresponding lanthanide ion. Characterization in solid state and solution, static magnetic studies, and ab initio computational studies were conducted to explore their coordination behavior.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Physical
Kyle M. Kirkpatrick, Benjamin H. Zhou, Philip C. Bunting, Jeffrey D. Rinehart
Summary: In this study, two new forms of iron oleate precursor were characterized, which can lead to reproducible and predictable reactivity, and produce tunable iron oxide nanoparticles.
CHEMISTRY OF MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Angelica P. Orlova, Jeremy D. Hilgar, Maximilian G. Bernbeck, Milan Gembicky, Jeffrey D. Rinehart
Summary: This study discusses the impact of dipolar coupling on the slow relaxation dynamics in lanthanide-based single-molecule magnets and proposes design principles for multinuclear molecular magnetism.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Kyle M. Kirkpatrick, Benjamin H. Zhou, Philip C. Bunting, Jeffrey D. Rinehart
Summary: Magnetization is a measurable property of materials that provides information about their electronic structure, phase purity, and impurities. Superparamagnetism, a size-dependent property of magnetic materials, has been underexplored in the field of quantum materials. In this study, a statistical model is used to analyze a dataset of variable-size superparamagnetic Fe3O4 particles. The results show that parameters of the intrinsic probability distribution, such as the maximum susceptibility, are more suitable for describing the superparamagnetic behavior compared to standard measures like saturation magnetization. This analysis has potential applications in synthesis diagnostics and prediction of new properties and functionality.
Article
Materials Science, Multidisciplinary
Liana S. Alves, Linfeng Chen, Carl E. Lemmon, Milan Gembicky, Mingjie Xu, Alina M. Schimpf
Summary: Metal oxide frameworks composed of the Preyssler anion were synthesized and infiltrated with polyethylene glycol, which allow them to be dissolved in water to form films or gels. The mechanical properties of these composites were found to depend on the water content and hydrogen-bonding within the water network.
ACS MATERIALS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Yijun Xie, Kelsey A. Krug, Kristine S. Cay, Mark Kalaj, Naneki C. McCallum, Zofia E. Siwicka, Zhao Wang, Nathan C. Gianneschi, Michael D. Burkart, Jeffrey D. Rinehart
Summary: Enzymes are a valuable source of inspiration for catalyst development due to their high catalytic activity and substrate specificity. The authors successfully synthesized a variant of L-DOPA polymer with high peroxidase-like activity by introducing mesoporosity and iron ion chelation. The polydopamine-based materials demonstrate strong potential as a versatile redox-catalysis platform, showing robustness and redox versatility despite redox changes and presence of radical species.
Article
Chemistry, Multidisciplinary
Hankyeol Jung, Alina M. Schimpf
Summary: The study introduces a method for photochemical conversion of inverse spinel iron oxides to mixed-valent magnetite phase with controlled Fe2+ composition. Through UV irradiation and sacrificial reductants, topotactic reduction of nanocrystals to form Fe3O4 can be achieved, resulting in increased magnetization and characteristic magnetic features.
Article
Chemistry, Inorganic & Nuclear
Alex J. Mantanona, Daniel R. Tolentino, Kristine S. Cay, Milan Gembicky, Rodolphe Jazzar, Guy Bertrand, Jeffrey D. Rinehart
DALTON TRANSACTIONS
(2020)
Meeting Abstract
Chemistry, Multidisciplinary
Jeffrey Rinehart, Benjamin Zhou
ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY
(2019)
