Article
Chemistry, Physical
Timothy P. Pollock, Cody W. Schlenker
Summary: This study investigated the dynamics of photoexcited conduction band electron trapping and recombination processes in CH3NH3PbI2 films using transient absorption spectroscopy. The researchers found that hot carrier dynamics can be differentiated from changes in trapped and free electron populations by varying the energy of the push pulse. The results have important implications for the design of passivation strategies in perovskite photovoltaics.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Materials Science, Multidisciplinary
Ryota Ishii, Akira Yoshikawa, Mitsuru Funato, Yoichi Kawakami
Summary: This study reevaluates the substitutional Mg acceptor binding energy of AlN and finds that it is well below 500 meV. The results have significant implications for the semiconductor applications of AlN.
Article
Chemistry, Multidisciplinary
Chloe Simha, Gabriela Herrero-Saboya, Luigi Giacomazzi, Layla Martin-Samos, Anne Hemeryck, Nicolas Richard
Summary: Nitrogen is commonly used in silicon to suppress the formation of defects. However, identifying specific nitrogen-related defects using spectroscopic methods is challenging.
Article
Chemistry, Physical
Lei Gao, Yong Zhang, Xin Wei, Ting Zheng, Weijie Zhao, Xinhai Zhang, Junpeng Lu, Zhenhua Ni, Hongwei Liu
Summary: Organic-inorganic halide perovskites are promising materials for high-performance photovoltaics. The regulatory mechanisms of the performance of perovskites have been investigated through potassium iodide doping, which includes passivating surface states, regulating carrier recombination and transport by varying different trap states, and effectively restraining defect penalty. Under the optimal doping concentration, a significant increase in conductivity and radiative efficiency is achieved.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Erin S. Grant, Liam T. Hall, Lloyd C. L. Hollenberg, Gawain McColl, David A. Simpson
Summary: In this study, the magnetic properties of ferritin, the primary storage protein in the body, were systematically studied using diamond-based quantum spin relaxometry. An anomalous magnetic behavior was observed at relatively low iron loads due to a morphological change in the iron core of ferritin. The inclusion of this morphological change in a theoretical model was supported by electron microscopy studies and provided evidence for the magnetic consequence of the morphological change.
Article
Chemistry, Multidisciplinary
Ye-Jin Kim, Oh-Hoon Kwon
Summary: By combining cathodoluminescence with ultrafast electron microscopy, researchers achieved high sensitivity measurement of color centers in nanodiamonds, revealing charge transfer mechanisms among color centers and providing new insights for energy conversion control in areas such as quantum dots and single-photon sources.
Article
Physics, Applied
T. Luo, L. Lindner, R. Blinder, M. Capelli, J. Langer, V. Cimalla, F. A. Hahl, X. Vidal, J. Jeske
Summary: Single substitutional nitrogen atoms N-s(0) are necessary to create nitrogen-vacancy (NV) centers in diamonds. A method based on absorption spectroscopy in the UV-Visible range is presented for the determination of N-s(0) concentration. The method allows for rapid and accurate determination of N-s(0) densities, even in samples with varying concentrations. It has been cross-checked with electron paramagnetic resonance and found to be reliable.
APPLIED PHYSICS LETTERS
(2022)
Article
Engineering, Environmental
Youpeng Li, Lingzhi Zhang
Summary: This study presents an oxygen vacancy-mediated nitrogen doping strategy to modify the surface structure of TiO2 nano-particles, achieving high doping concentration and constructing a TiO2@TiO2-x-SN core@shell heterojunction. This structure favors the diffusion kinetics of Li+ and reduces the band gap, facilitating electron transport. The TiO2@TiO2-x-SN electrode exhibits excellent cycling performance and capacity retention.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Sai Shruthi Murali, Joseph K. Gallaher, Celine Janiseck, Elliot J. Tay, Isabella Wagner, Karen E. Thorn, Aleksandra Ilina, Ronnie R. Tamming, Jiayu Wang, Clement Sester, Joshua J. Sutton, Michael B. Price, Keith C. Gordon, Kai Chen, Xiaowei Zhan, Justin M. Hodgkiss, Paul A. Hume
Summary: The control over singlet and triplet exciton populations is crucial for organic semiconductor technologies. This study investigates the rate of intersystem crossing (ISC) and demonstrates the occurrence of intramolecular triplet formation in both solution and solid state. It is found that structural distortions in disordered films lead to increased spin-orbit coupling, enabling rapid ISC. The proposal also reveals the role of rotational flexibility and conformational disorder in accelerating ISC. Overall, this work sheds light on the factors affecting ISC and provides a framework for molecular control over spin states.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Physics, Applied
King Cho Wong, San Lam Ng, Kin On Ho, Yang Shen, Jiahao Wu, Kwing To Lai, Man Yin Leung, Wai Kuen Leung, Durga Bhaktavatsala Rao Dasari, Andrej Denisenko, Joerg Wrachtrup, Sen Yang
Summary: Single color centers in solid have emerged as a promising physical platform for quantum information science. This work proposes and demonstrates a distinct high-temperature annealing (HTA) approach for creating high-quality nitrogen vacancy (N-V) centers in implantation-free diamonds. The created N-V centers possess stable and Fourier-transform-limited optical spectra, and HTA strongly reduces noise sources and improves decoherence time and sensitivity. The study also explores the vacancy activation and defect reformation in spin baths and color centers.
PHYSICAL REVIEW APPLIED
(2022)
Article
Chemistry, Analytical
Sergey Kudryashov, Pavel Danilov, Evgeny Kuzmin, Nikita Smirnov, Alexey Gorevoy, Victor Vins, Daniil Pomazkin, Petr Paholchuk, Andrey Muratov, Alexey Kirichenko, Nikolay Rodionov, Evgeny Vasil'ev
Summary: Tightly focused 515-nm, 0.3-ps laser pulses were used to modify the crystalline structure of a high-pressure, high-temperature synthesized diamond. The modified microregions in the crystal zones showed diminished IR absorption and increased absorption coefficients in the visible range. The photoluminescence yield was strongly enhanced, indicating the conversion of impurity atoms into quantum-emitter centers.
Article
Chemistry, Multidisciplinary
Wenchao Wang, Ying Tao, Jinchen Fan, Zhiping Yan, Huan Shang, David Lee Phillips, Ming Chen, Guisheng Li
Summary: Ultrafast excited-state decay and intrinsic charge carrier recombination restrain the enhancement of photoactivity for solar-to-H-2 production. A CdS-F/G photocatalyst is synthesized for visible-light-driven hydrogen generation, demonstrating ultrafast interfacial charge transfer and self-trapping process. In-situ dynamic study reveals sub-microsecond-lived excited states, interfacial electron transfer, and hole trapping, enhancing charge separation and increasing photoactivity. The CdS-F/G photocatalyst exhibits high stability and achieves a quantum efficiency of 7.24% at 420 nm.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Jumi Park, Jooyoung Sung, Dongho Kim
Summary: In this study, the charge transfer (CT) processes in donor-pyreneacceptor (DPA) molecules were deciphered using various time-resolved spectroscopic measurements. The ultrafast CT rate of approximately 200 fs in DPA molecules was observed, indicating isoenergetic potential surfaces for LE and CT states. Strong electronic coupling between the LE and CT states was found upon the introduction of the acceptor to the pyrene moiety in DPA systems.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Physics, Applied
M. Huebler, W. Belzig
Summary: Quantum transport in the presence of time-dependent drives is dominated by quantum interference and many-body effects at low temperatures. For a periodic driving, the analysis of the full counting statistics revealed the elementary events that determine the statistical properties of the charge transport. However, recent studies have focused on transport by few-cycle light pulses and the need for a statistical interpretation has become evident.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Physical
Ashley J. Redman, Gabriel Moise, Sabine Richert, Erin J. Viere, William K. Myers, Michael J. Therien, Christiane R. Timmel
Summary: The study investigates the significance of photoexcited triplet states of porphyrin in various fields and the key spectroscopic tool for quantifying spin delocalization. The challenges and potential developments of the methodology for analyzing experimental data of a series of porphyrin monomers are discussed using EPR and quantum chemical calculations.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Zhaoyang Liu, Yunbin Hu, Wenhao Zheng, Can Wang, Walid Baaziz, Fanny Richard, Ovidiu Ersen, Mischa Bonn, Hai Wang, Akimitsu Narita, Artur Ciesielski, Klaus Muellen, Paolo Samori
Summary: The precise synthesis of graphene nanoribbons (GNRs) with controlled width and edge structures is beneficial for overcoming the limitations of graphene, and GNRs with open-edge structures allow faster ion diffusion, showing great potential for energy storage systems. However, current solution-synthesized GNRs suffer from aggregation, which restricts their applications. Therefore, a facile and scalable approach is needed to exfoliate GNRs from aggregates. Here, a high-shear-mixing approach is demonstrated to untie GNR bundles into individual nanoribbons.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Cheng Zeng, Wenhao Zheng, Hong Xu, Silvio Osella, Wei Ma, Hai Wang, Zijie Qiu, Ken-ichi Otake, Wencai Ren, Huiming Cheng, Klaus Muellen, Mischa Bonn, Cheng Gu, Yuguang Ma
Summary: Electrochemical deposition is an efficient technique for preparing conjugated polymer films on electrodes, allowing control over film thickness, crystal size, and crystal orientation. The films produced by this method have a unique crystal structure and exhibit exceptional carrier and exciton migration.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Max Lukas, Ellen H. G. Backus, Mischa Bonn, Maksim Grechko
Summary: SFG vibrational spectroscopy is a powerful technique to study interfaces. However, implementing this technique is challenging. In this study, a collinear PR-SFG setup using a displaced Sagnac interferometer is developed, which allows independent control of time delay and intensity and provides long-time phase stabilization for the measured signal.
JOURNAL OF PHYSICAL CHEMISTRY A
(2022)
Article
Chemistry, Physical
Max Lukas, Ralph Schwidetzky, Rosemary J. Eufemio, Mischa Bonn, Konrad Meister
Summary: The exceptional ice nucleation activity of bacterial ice nucleators is highlighted in this perspective, emphasizing the importance of functional aggregation of ice-nucleating proteins (INPs) anchored to the outer bacterial cell membrane. It is crucial to consider the role of the bacterial cell membrane and environmental conditions in facilitating precise functional aggregation of INPs, and interdisciplinary approaches combining various tools are needed to study changes at the protein level.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Chemistry, Multidisciplinary
Junren Wang, Shuai Fu, Heng Zhang, Robert Graf, Henry Halim, Shuai Chen, Wenhao Zheng, Mischa Bonn, Katharina Landfester, Andreas Riedinger, Hai Wang
Summary: This study reports a novel solution-processed approach to fabricate high-quality, large-area alpha-Ag2S thin films. Ultrafast terahertz conductivity measurements show efficient charge transport in the films. Additionally, introducing poly(vinyl alcohol) enables the synthesis of free-standing alpha-Ag2S thin films for flexible optoelectronics.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Shuai Fu, Enquan Jin, Hiroki Hanayama, Wenhao Zheng, Heng Zhang, Lucia Di Virgilio, Matthew A. Addicoat, Markus Mezger, Akimitsu Narita, Mischa Bonn, Klaus Muellen, Hai Wang
Summary: Two-dimensional covalent organic frameworks (2D COFs) are crystalline porous polymers with well-defined open nanochannels. This study reveals that TPB-TFB COF thin films exhibit high photoconductivity with long charge scattering time and high charge carrier mobility at room temperature.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Physics, Multidisciplinary
Wenhao Zheng, Boya Sun, Dongqi Li, Sai Manoj Gali, Heng Zhang, Shuai Fu, Lucia Di Virgilio, Zichao Li, Sheng Yang, Shengqiang Zhou, David Beljonne, Minghao Yu, Xinliang Feng, Hai Wang, Mischa Bonn
Summary: MXenes are promising layered materials for electrochemical energy storage and (opto-)electronic applications. By combining ultrafast terahertz and static electrical transport measurements, a unifying picture of charge transport in MXenes has been presented, revealing both short- and long-range transport characteristics.
Article
Chemistry, Multidisciplinary
Lin Yang, Ji Ma, Wenhao Zheng, Silvio Osella, Joern Droste, Hartmut Komber, Kun Liu, Steffen Boeckmann, David Beljonne, Michael Ryan Hansen, Mischa Bonn, Hai Wang, Junzhi Liu, Xinliang Feng
Summary: This study reports a solution synthesis method for curved graphene nanoribbons (GNRs) with hybrid edge structures. The GNRs demonstrate unique nonplanar conformation and electronic properties, including a narrow optical bandgap and high carrier mobility.
Article
Chemistry, Physical
Hao Lu, Luca Bellucci, Shumei Sun, Daizong Qi, Marta Rosa, Ruediger Berger, Stefano Corni, Mischa Bonn
Summary: The assembly mechanism of Aβ peptides at hydrophobic interfaces depends on the pH, with acidic conditions promoting the formation of extended β-strand fibrils and facilitating macroscopic assembly.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Jing Chen, Yongkang Wang, Benjamin Leibauer, Takakazu Seki, Konrad Meister, Yuki Nagata, Mischa Bonn
Summary: This study combines the ice nucleation tuning capability of polyelectrolytes with mussel-inspired adhesives to achieve robust surface functionalization with controlled heterogeneous ice nucleation (HIN). By integrating surface-binding catechol derivatives into different polyelectrolytes, the ice nucleation process is tuned, and the mechanism of interaction between water molecules and the functionalized surface is revealed using interfacial molecular spectroscopy.
Article
Chemistry, Multidisciplinary
Johannes Hunger, Jan Schaefer, Patrick Ober, Takakazu Seki, Yongkang Wang, Leon Praedel, Yuki Nagata, Mischa Bonn, Douwe Jan Bonthuis, Ellen H. G. Backus
Summary: Understanding the collective behavior of ions at charged surfaces is crucial for geological and electrochemical processes. In this study, sum-frequency generation (SFG) spectroscopy was used to investigate the symmetry-breaking of water molecules at a charged silica surface in contact with different alkaline metal chloride solutions. The results demonstrate that the water response varies with the cation, with LiCl showing a significantly enhanced SFG response compared to CsCl. Further analysis indicates that the effect of different salts on the optical response is indirectly mediated by the reorganization of interfacial water.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Pankaj Seliya, Mischa Bonn, Maksim Grechko
Summary: This study focuses on the interaction between quantum-mechanical systems and fluctuating thermal environments, providing insights into their coupling through a combined experimental and theoretical approach. The experimental part involves spectroscopy measurements to directly observe the coupling between quantum oscillators and low-frequency modes. The theoretical part introduces a mixed quantum-classical formalism to describe the sample response. This approach enables the quantitative and mode-specific analysis of coupled quantum and classical dynamics in complex chemical systems.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Physical
Yongkang Wang, Yuki Nagata, Mischa Bonn
Summary: Graphene, as a transparent two-dimensional conductive electrode, has brought new perspectives to electrochemical systems. The substrate plays a crucial role in determining the water organization and wetting behavior of graphene. Surface-specific spectroscopy study reveals that the charging of graphene is decoupled from the charging of its substrate.
FARADAY DISCUSSIONS
(2023)
Article
Engineering, Electrical & Electronic
Xuan Zhou, Fan Shi, Jiafeng Lu, Mengjun Xu, Mengdie Hou, Mischa Bonn, Xiaomin Liu, Xianglong Zeng
Summary: This paper proposes a method for producing femtosecond visible doughnut beams by integrating nonlinear frequency conversion and in-fiber mode conversion techniques. This method allows for dynamic manipulation of vector visible beams in optical fibers.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Gabriele C. Sosso, Prerna Sudera, Anna T. Backes, Thomas F. Whale, Janine Froehlich-Nowoisky, Mischa Bonn, Angelos Michaelides, Ellen H. G. Backus
Summary: By conducting experiments and simulations, this study systematically investigates the ice-nucleating ability of cholesterol in both crystalline and disordered self-assembled monolayers. A sweet spot in terms of the surface coverage of the monolayers is identified, where cholesterol enhances the structural order of interfacial water molecules and maximizes its ability to nucleate ice.