Article
Chemistry, Multidisciplinary
Shan-Wen Cheng, Ding Xu, Haowen Su, James M. Baxter, Luke N. Holtzman, Kenji Watanabe, Takashi Taniguchi, James C. Hone, Katayun Barmak, Milan Delor
Summary: In this study, we use excitons in two-dimensional materials as sensors to achieve visible-light imaging of phonon polariton propagation in hexagonal boron nitride, and observe the phenomenon of co-propagation of excitons and phonon polaritons. This research provides a new method for high-precision imaging of polar excitations and a new mechanism for realizing ballistic exciton transport at room temperature.
Article
Multidisciplinary Sciences
Ding Xu, Arkajit Mandal, James M. Baxter, Shan-Wen Cheng, Inki Lee, Haowen Su, Song Liu, David R. Reichman, Milan Delor
Summary: Semiconductor excitations can form exciton-polaritons with light-like energy flow and matter-like interactions. By using nonlinear momentum-resolved optical approach, the authors directly image the exciton-polaritons in real space on femtosecond scales. It is found that exciton-phonon interactions result in a renormalization of exciton-polariton velocities, but ballistic transport can be maintained for half-exciton polaritons. Upon increasing the excitonic character, rapid decoherence leads to diffusive transport.
NATURE COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Qirui Liu, Ke Wei, Yuxiang Tang, Zhongjie Xu, Xiang'ai Cheng, Tian Jiang
Summary: The excited-state dynamics in layered tungsten disulfide (WS2) were studied using transient absorption microscopy, which revealed the ultrafast hot carrier expansion and its potential in improving carrier harvesting. A cascaded transport model was proposed to explain the carrier diffusion mechanism in this system.
Article
Multidisciplinary Sciences
Haonan Lin, Hyeon Jeong Lee, Nathan Tague, Jean-Baptiste Lugagne, Cheng Zong, Fengyuan Deng, Jonghyeon Shin, Lei Tian, Wilson Wong, Mary J. Dunlop, Ji-Xin Cheng
Summary: The study presents a system for acquiring high-resolution SRS spectra using a polygon scanner, while significantly improving signal-to-noise ratio through the use of a spatial-spectral residual learning network. The authors demonstrate high-speed imaging and tracking of multiple biomolecules in the fingerprint region using a polygon-based ultrafast delay scanner and deep learning framework.
NATURE COMMUNICATIONS
(2021)
Editorial Material
Optics
Kenneth K. Y. Wong, Xiaoming Wei, Na Ji, Dario Polli, Benjamin J. Vakoc
Summary: This feature issue of Optics Express gathers 20 articles that present the latest advancements in ultrafast optical imaging. The review provides a summary of these articles, encompassing the range of technologies and applications in the field of ultrafast optical imaging.
Article
Chemistry, Multidisciplinary
Thomas Siday, Fabian Sandner, Samuel Brem, Martin Zizlsperger, Raul Perea-Causin, Felix Schiegl, Svenja Nerreter, Markus Plankl, Philipp Merkl, Fabian Mooshammer, Markus A. Huber, Ermin Malic, Rupert Huber
Summary: This study demonstrates the Mott transition from an exciton gas to an electron-hole plasma in two-dimensional transition metal dichalcogenides. Using ultrafast polarization nanoscopy, the researchers observed the transition of dark exciton recombination from monomolecular to bimolecular as the carrier density increased. Their results provide direct evidence of the strong inhomogeneity in stacked monolayers.
Article
Optics
Moritz B. Heindl, Nicholas Kirkwood, Tobias Lauster, Julia A. Lang, Markus Retsch, Paul Mulvaney, Georg Herink
Summary: The study utilizes the quantum-confined Stark-effect to encode ultrafast electric near-fields into colloidal quantum dot luminescence and introduces a new microscopic imaging method called Quantum-probe Field Microscopy (QFIM). This approach allows for spatial and temporal resolution of Terahertz resonance and waveguide excitations in the sub-wavelength regime, providing a direct route towards ultrafast field imaging of complex nanodevices.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Seongkwang Bae, Sanghee Nah, Doeon Lee, Muhammad Sajjad, Nirpendra Singh, Ku Min Kang, Sanghoon Kim, Geun-Ju Kim, Jaekyun Kim, Hionsuck Baik, Kyusang Lee, Sangwan Sim
Summary: Strongly bound excitons, characteristic of 2D semiconductors, are observed and theoretically confirmed in mono-, bi-, and tri-layer platinum diselenide (PtSe2) single crystals. The excitons in PtSe2 dominate the transient broadband response, with a redshift in the transient spectrum as the band-gap redshifts the exciton resonance. This study provides novel insights into exciton photophysics in platinum dichalcogenides.
Article
Chemistry, Multidisciplinary
Junling Chen, Hongru Li, Qiang Wu, Tan Zhao, Haijiao Xu, Jiayin Sun, Feng Liang, Hongda Wang
Summary: P-glycoproteins (P-gps) over-expressed in cancer cells play a crucial role in multi-drug resistance. By using a specific inhibitor, tariquidar modified with TAMRA, the study revealed that P-gps can facilitate pumping efficiency by forming functional platforms through aggregation. The specific distribution patterns of P-gps might serve as potential biomarkers for tumor and drug therapy screening.
Review
Pharmacology & Pharmacy
Vernon LaLone, Doug Smith, Jennifer Diaz-Espinosa, Gus R. Rosania
Summary: Raman confocal microscopes are used to visualize the distribution of small molecule drugs within cells, providing insights into their transport phenomena. Chemical imaging techniques reveal the formation of stable complexes or precipitates of lipophilic drugs inside cells. Raman chemical imaging methods allow measurement and mapping of drug molecules at a microscopic, subcellular level.
ADVANCED DRUG DELIVERY REVIEWS
(2023)
Article
Chemistry, Physical
Giacomo Fanciullo, Irene Conti, Pascal Didier, Andrey Klymchenko, Jeremie Leonard, Marco Garavelli, Ivan Rivalta
Summary: A new macroscopic model incorporating contributions from molecular aggregate quenchers was introduced to analyze the decay process of exciton density. The study demonstrated that the model is applicable to molecular systems with ultrafast decays, and the presence of molecular aggregate quenchers can be monitored by evaluating the long time decay of exciton density. This model could potentially be used in future studies for global fitting of experimental data with support from first-principles simulations.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Yue Wu, Ho-Fai Chau, Yik-Hoi Yeung, Waygen Thor, Hei-Yui Kai, Wai-Lun Chan, Ka-Leung Wong
Summary: In this study, a novel synthetic method for the efficient preparation of prefunctionalized core porphyrins and the controllable construction of various valent porphyrin-peptide conjugates was reported. Compared to traditional methods, this approach is faster, greener, and requires only one final-stage purification.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Guoquan Gao, Lan Jiang, Bofeng Xue, Fei Yang, Ti Wang, Yan Wan, Tong Zhu
Summary: Tracking the spatiotemporal distribution of photoexcited hot electrons using ultrafast microscopy provides insight into the competitive relationship between transport and cooling mechanisms. The study reveals that interfacial heat dissipation dominates in the nonequilibrium state evolution below the ballistic length, while hot electron transport competes with electron-phonon coupling. This work enriches the toolbox of ultrafast techniques and offers guidance for the rational design and optimization of micro- and nanodevices.
Article
Chemistry, Physical
Vesna Eric, Jorge Luis Castro, Xinmeng Li, Lolita Dsouza, Sean K. Frehan, Annemarie Huijser, Alfred R. Holzwarth, Francesco Buda, G. J. Agur Sevink, Huub J. M. de Groot, Thomas L. C. Jansen
Summary: Chlorosomes from green bacteria have efficient light capture and energy transfer abilities, inspiring developments in artificial light-harvesting and molecular optoelectronics. We examine two different organizations of the molecular building blocks and show how they affect light capture and energy transfer, potentially allowing the bacteria to adapt to changes in light conditions. Spectral simulations reveal how changes in the helicity of chlorosomal aggregates alter energy transfer, with contrasting energy pathways in different chlorosomes.
JOURNAL OF PHYSICAL CHEMISTRY B
(2023)
Article
Multidisciplinary Sciences
Mykola Telychko, Shayan Edalatmanesh, Kai Leng, Ibrahim Abdelwahab, Na Guo, Chun Zhang, Jesus Mendieta-Moreno, Matyas Nachtigall, Jing Li, Kian Ping Loh, Pavel Jelinek, Jiong Lu
Summary: This study demonstrates the sub-angstrom resolution imaging of the atomic arrangement in two-dimensional Ruddlesden-Popper hybrid perovskites using tip-functionalized scanning tunneling microscopy (STM) and noncontact atomic force microscopy (ncAFM). The imaging reveals the atomic reconstruction of the inorganic lattice and the cooperative reordering of surface organic cations, as well as the variation of the electrostatic potential across twin-domain walls.