Article
Chemistry, Multidisciplinary
Brandon J. Furey, Benjamin J. Stacy, Tushti Shah, Rodrigo M. Barba-Barba, Ramon Carriles, Alan Bernal, Bernardo S. Mendoza, Brian A. Korgel, Michael C. Downer
Summary: Colloidal nanocrystalline silicon quantum dots (nc-SiQDs) excited by two-photon in the near-infrared (NIR) range have potential applications in deep biological imaging. The two-photon absorption (2PA) cross section of colloidal nc-SiQDs is measured, and it is found to be smaller for smaller diameter nanocrystals. The efficiencies of nc-SiQDs for bioimaging using two-photon excited photoluminescence (2PE-PL) are compared to other quantum dots and molecular fluorophores and found to be comparable or superior at greater depths.
Article
Chemistry, Multidisciplinary
Federica Ricci, Veronica Marougail, Oleg Varnavski, Yue Wu, Suyog Padgaonkar, Shawn Irgen-Gioro, Emily A. Weiss, Theodore Goodson
Summary: This study used femtosecond time-resolved two-photon near-field scanning optical microscopy to reveal the coherence involving a single cesium lead bromide perovskite QD at room temperature. The electron coherence on a single perovskite QD was found to have a relatively long lifetime compared to other nanoparticles, possibly due to the exciton fine structure. The unique optical properties of these perovskite QDs, including bright triplet exciton states, suggest their potential for quantum computing and information processing applications.
Article
Physics, Multidisciplinary
Nan-Nan Zhang, Li-Ya Zhou, Xiao Liu, Zhong-Chao Wei, Hai-Ying Liu, Sheng Lan, Zhao Meng, Hai-Hua Fan
Summary: The study demonstrates that ZnSe quantum dots have great potential for biological imaging, with good biocompatibility and a large two-photon absorption cross section.
Article
Optics
Saumya Biswas, S. J. van Enk
Summary: This article introduces a model for describing a type of two-photon detector consisting of one molecule that can detect two photons arriving sequentially in time. The detector model includes a Hamiltonian description for amplifying the microscopic change and converting it into a macroscopic signal.
Article
Chemistry, Physical
Mark W. B. Wilson, Minhal Hasham, Pournima Narayanan, Francisco Yarur Villanueva, Philippe B. Green, Christian J. Imperiale
Summary: Nanocrystal-sensitized triplet-fusion upconversion is an emerging strategy for converting long-wavelength, incoherent light to higher-energy output photons. The photophysics of tailor-functionalized CdSe nanocrystals were studied to understand energy transfer to surface anchored transmitter ligands, which can occur through correlated exciton transfer or sequential carrier hops. By reducing the barrier to hole-first sequential transfer, a significant acceleration of energy transfer was observed. This acceleration was found to be greater than the expected effect of increased carrier wave function leakage, indicating the dominance of sequential transfer under certain conditions. Transient photoluminescence measurements showed comparable quenching of NC band-edge and trap states by functionalization, suggesting a dynamic quasi-equilibrium allowing for extraction of photoexcitations even when a carrier is initially trapped.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Physics, Multidisciplinary
S. Moeller, L. Banszerus, A. Knothe, C. Steiner, E. Icking, S. Trellenkamp, F. Lentz, K. Watanabe, T. Taniguchi, L. I. Glazman, V. I. Fal'ko, C. Volk, C. Stampfer
Summary: The study finds that in bilayer graphene, orbital symmetric states have lower energy than orbital antisymmetric states, and there is a significant energy difference between them. Furthermore, the symmetric multiplet also exhibits energy splitting of its states due to lattice scale interactions.
PHYSICAL REVIEW LETTERS
(2021)
Article
Biochemistry & Molecular Biology
Ziyi Liu, Fei Li, Yi Luo, Ming Li, Guanghui Hu, Xianjuan Pu, Tao Tang, Jianfeng Wen, Xinyu Li, Weitao Li
Summary: High-photoluminescence graphene quantum dots were synthesized through a simple one-pot hydrothermal process and separated using dialysis bags of different molecular weights, resulting in four GQDs with varying sizes. As the size of the separated GQDs decreased, the intensity of the emission peak became stronger, with the smallest GQDs showing the most energetic PL intensity among the four separated GQDs. The PL energy of all separated GQDs shifted slightly, as supported by density functional theory calculations.
Article
Materials Science, Multidisciplinary
Zhiyuan Wei, Zihao Guan, Fang Liu, Yanyan Xue, Naying Shan, Yang Zhao, Lulu Fu, Zhipeng Huang, Jun Xu, Mark G. Humphrey, Chi Zhang
Summary: This study constructed covalently linked nanocomposites composed of graphene oxide (GO) and MoS2, WS2 quantum dots (QDs). These nanocomposites demonstrated significant fluorescence quenching and superior two-photon absorption (TPA) responses, indicating their promising potential in optical limiting applications and ultrafast photonic devices.
MATERIALS TODAY PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Colin Whisler, Gregory Holdman, D. D. Yavuz, Victor W. Brar
Summary: This study calculates the enhancement of two-photon spontaneous emission (2PSE) from trivalent and divalent rare earth ions in proximity to graphene and graphene nanoribbons using finite difference time domain simulations and direct computation of transition rates. The results show that with enhancement, 2PSE can reach 2.5% of the overall decay for Er3+. The use of graphene nanoribbons can also significantly increase the emission of free-space photon pairs from Er3+ at 3-3.2 μm via 2PSE. The study also highlights the impact of emitter size, assumed graphene mobility, and the internal energy structure of the ion on the degree of 2PSE enhancement achievable.
Article
Chemistry, Multidisciplinary
Emma L. Minarelli, Jonas B. Rigo, Andrew K. Mitchell
Summary: This article investigates a graphene-based two-channel charge-Kondo device and uncovers a rich phase diagram. It finds that the strong coupling pseudogap Kondo phase persists in the channel-asymmetric case. Furthermore, despite the vanishing density of states in the graphene leads, a finite linear conductance is observed at the frustrated critical point.
Article
Nanoscience & Nanotechnology
Pei-Chun Yeh, Genki Ohkatsu, Ryo Toyama, Phan Trong Tue, Kostya (Ken) Ostrikov, Yutaka Majima, Wei-Hung Chiang
Summary: The study demonstrates a simple and controlled fabrication method of graphene quantum dot (GQD)-based single-electron transistors (SETs) for photon detectors. The GQD-SETs fabricated enable photon detection with 410 nm excitation due to the photoluminescence emission capability of GQDs.
Article
Materials Science, Multidisciplinary
Y. Muniz, P. P. Abrantes, L. Martin-Moreno, F. A. Pinheiro, C. Farina, W. J. M. Kort-Kamp
Summary: This study investigates the spontaneous decay of a quantum emitter near single-walled carbon nanotubes and graphene-coated wires. The results show enhanced generation of entangled states in single-walled carbon nanotubes and predict significantly higher emission rates compared to free space. The findings provide a basis for a new material platform for on-chip quantum information technologies.
Article
Engineering, Environmental
Zhongda Yan, Xiaonan Yang, Iseult Lynch, Fuyi Cui
Summary: This study compared the acute effects of graphene oxide (GO) and graphene oxide quantum dots (GOQDs) on Microcystis aeruginosa, finding that GOQDs dispersed more effectively in water and had a stronger impact on cells. Higher concentrations led to cell structure damage and indirect toxicity through nutrient depletion.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Chemistry, Physical
Jiayao Zhu, Luxiang Wang, Xuemeng Gan, Tingting Tang, Fuwei Qin, Wanxia Luo, Qiqi Li, Nannan Guo, Su Zhang, Dianzeng Jia, Huaihe Song
Summary: This study prepares a novel edge-enriched carbon nanofiber fabric through partial hydrolysis of electrospun graphene quantum dots (GQDs)/polyacrylonitrile fabric, and explores its energy storage ability and mechanism. The results show that the fabric exhibits excellent electrochemical activity, ultrafast pseudocapacitive performance, and good cycle stability due to the unique electronic structure and abundant functional groups of the edge sites.
ENERGY STORAGE MATERIALS
(2022)
Article
Chemistry, Physical
G. T. Oyeniyi, Iu. A. Melchakova, L. A. Chernozatonskii, P. V. Avramov
Summary: Based on DFT calculations, the structure and properties of nanodiamond islands confined between two graphene fragments were theoretically explored. It was found that NDI-c2G lattices can be stabilized by a support and formed through fusion of aromatic molecules with graphene fragments. Furthermore, the NDI-c2G regions exhibit low- or anti-aromaticity and localized frontier orbitals. This study suggests that NDI-c2G can be considered as strongly-correlated entangled hybrid quantum dots with great potential for advanced quantum applications.
