A5042106312- 2D Materials and Applications
- Perovskite Materials and Applications
- Graphene research and applications
- Laser-Ablation Synthesis of Nanoparticles
- Mechanical and Optical Resonators
- Advanced Sensor and Energy Harvesting Materials
- Diamond and Carbon-based Materials Research
- Topological Materials and Phenomena
- Fullerene Chemistry and Applications
- Luminescence Properties of Advanced Materials
- Molecular Junctions and Nanostructures
- Advanced MEMS and NEMS Technologies
- Photonic and Optical Devices
- Silicon Nanostructures and Photoluminescence
- Quantum Dots Synthesis And Properties
- Conducting polymers and applications
- Orbital Angular Momentum in Optics
- Nanowire Synthesis and Applications
- Metamaterials and Metasurfaces Applications
- MXene and MAX Phase Materials
- Plasmonic and Surface Plasmon Research
- Laser-induced spectroscopy and plasma
- Advanced X-ray Imaging Techniques
- Multiferroics and related materials
- Advanced Nanomaterials in Catalysis
University of Wisconsin–Madison
1994-2025
Stanford University
2020-2024
Nanjing Forestry University
2024
Chongqing University
2024
Jiangxi University of Science and Technology
2023
Shenzhen Institute of Information Technology
2016-2022
Harbin Institute of Technology
2016-2022
SLAC National Accelerator Laboratory
2020-2021
University of California, Berkeley
2004-2020
Center for Nanoscale Science and Technology
2015-2020
Two-dimensional (2D) transition metal dichalcogenides have emerged as a promising material system for optoelectronic applications, but their primary figure of merit, the room-temperature photoluminescence quantum yield (QY), is extremely low. The prototypical 2D molybdenum disulfide (MoS2) reported to maximum QY 0.6%, which indicates considerable defect density. Here we report on an air-stable, solution-based chemical treatment by organic superacid, uniformly enhances and minority carrier...
Out-of-plane ferroelectricity with a high transition temperature in ultrathin films is important for the exploration of new domain physics and scaling down memory devices. However, depolarizing electrostatic fields interfacial chemical bonds can destroy this long-range polar order at two-dimensional (2D) limit. Here we report experimental discovery locking between out-of-plane dipoles in-plane lattice asymmetry atomically thin In_{2}Se_{3} crystals, stabilization mechanism leading to our...
A phonon merry-go-round Chirality is associated with the breaking of symmetry, often described as left- or right-handed behavior. Such asymmetry can be seen, for example, in electronic responses particular materials reactions between chemical species. Zhu et al. observed a chiral mode monolayer transition metal dichalcogenide WSe 2 , detected spectroscopically circular dichroism phonon-assisted holes. Phonon chirality could used to control electron-phonon coupling and/or phonon-driven...
Second-harmonic generation (SHG) has found extensive applications from hand-held laser pointers to spectroscopic and microscopic techniques. Recently, some cleavable van der Waals (vdW) crystals have shown SHG arising a single atomic layer, where the SH light elucidated important information such as grain boundaries electronic structure in these ultra-thin materials. However, despite inversion asymmetry of typical crystal stacking restores symmetry for even numbers layers leading an...
Abstract Advances in complex oxide heteroepitaxy have highlighted the enormous potential of utilizing strain engineering via lattice mismatch to control ferroelectricity thin-film heterostructures. This approach, however, lacks ability produce large and continuously variable states, thus limiting for designing tuning desired properties ferroelectric films. Here, we observe explore dynamic strain-induced SrTiO 3 by laminating freestanding films onto a stretchable polymer substrate. Using...
Abstract The research on emerging layered two-dimensional (2D) semiconductors, such as molybdenum disulfide (MoS 2 ), reveals unique optical properties generating significant interest. Experimentally, these materials were observed to host extremely strong light-matter interactions a result of the enhanced excitonic effect in two dimensions. Thus, understanding and manipulating excitons are crucial unlocking potential 2D for future photonic optoelectronic devices. In this review, we unravel...
Carbyne with one-dimensional sp -hybridized carbon atoms is synthesized under ambient conditions in the laboratory.
Optical selection rule fundamentally determines the optical transition between energy states in a variety of physical systems from hydrogen atoms to bulk crystals such as GaAs. It is important for optoelectronic applications lasers, energy-dispersive X-ray spectroscopy and quantum computation. Recently, single layer metal dichalcogenide (TMDC) exhibits valleys momentum space with nontrivial Berry curvature excitons large binding energy. However, it unclear how unique valley degree freedom...
Copper(I) oxide (Cu 2 O) is an attractive photocatalyst because of its abundance, low toxicity, environmental compatibility, and narrow direct band gap, which allows efficient light harvesting. However, Cu O exhibits poor photocatalytic performance photostability short electron diffusion length hole mobility. Here, it demonstrated that nanodiamond (ND) can greatly improve the hydrogen evolution reaction (HER) p‐type nanocrystals by nanocomposition. Compared with pure nanocrystals, this...
Despite extensive work on the fluorescence behavior of graphite and graphene quantum dots, reports luminescence nanodiamonds are so far much fewer. In fact, distinctly different from carbon dots with nondiamond phases in both crystalline structure electronic structure. Here, we report that fluorescent nanodiamond colloids exhibit strong visible emissions their characteristics can be summarized as follows: (i) is unrelated to size effect (ii) obviously excitation-dependent fluorescence, (iii)...
Abstract Engineering the substrate of 2D transition metal dichalcogenides can couple quasiparticle interaction between material and substrate, providing an additional route to realize conceptual quantum phenomena novel device functionalities, such as realization a 12‐time increased valley spitting in single‐layer WSe 2 through interfacial magnetic exchange field from ferromagnetic EuS band‐to‐band tunnel field‐effect transistors with subthreshold swing below 60 mV dec −1 at room temperature...
Excitons in two-dimensional (2D) materials are tightly bound and exhibit rich physics. So far, the optical excitations 2D semiconductors dominated by Wannier-Mott excitons, but molecular systems can host Frenkel excitons (FE) with unique properties. Here, we report a strong response class of monolayer J-aggregates. The exciton exhibits giant oscillator strength absorption (over 30% for monolayer) at resonance, as well photoluminescence quantum yield range 60-100%. We observe evidence...
Pancharatnam-Berry (PB) metasurfaces have intrigued a great deal of interest in recent years for anomalous reflection/refraction, vortex plate, orbital angular momentum, flat lens, photonic spin hall effect (PSHE), holograms and reflect/transmit arrays. However, almost all designs are restricted to fixed electrical performance/functionality once the design is finished. Here, we report first time strategy PB metasurface with agile working frequency by involving each meta-atom tunable PIN...
The discovery of atomically thin layered materials such as graphene and transition metal dichalcogenides has unveiled the unique exploration novel fundamental physics device applications in two-dimensions. Characterization their crystal symmetry subsequent electronic properties are prominent to realize full potential these reduced dimensional systems, which fundamentally determine topology, chirality rich interfacial physics. Second harmonic generation (SHG), a nonlinear optical effect, is...
Layered materials have rapidly established themselves as intriguing building blocks for next-generation photodetection platforms in view of their exotic electronic and optical attributes. However, both relatively low mobility heavier electron effective mass limit layered high-performance applications. Herein, we employed nanodiamonds (NDs) to promote the performance multilayer In2Se3 photodetectors first time. This hybrid NDs–In2Se3 photodetector showed a tremendous promotion comparison...
Controlling the shape, geometry, density, and orientation of nanomaterials is critical to fabricate functional devices. However, there limited control over morphological directional characteristics presynthesized nanomaterials, which makes them unsuitable for developing devices practical applications. Here, we address this challenge by demonstrating vertically aligned polarized piezoelectric nanostructures from biological nanofibers, M13 phage, with orientation, polarization direction,...
Monoclinic Gd2O3:Eu3+ nanoparticles (NPs) possess favorable magnetic and optical properties for biomedical application. However, how to obtain small enough NPs still remains a challenge. Here we combined the standard solid-state reaction with laser ablation in liquids (LAL) technique fabricate sub-10 nm monoclinic explained their formation mechanism. The obtained exhibit bright red fluorescence emission can be successfully used as probe cells imaging. In vitro vivo resonance imaging (MRI)...
We have demonstrated that nanodiamonds (NDs), as oxidation and reduction catalysts, possess intrinsic enzyme mimetic properties of oxidase, peroxidase catalase, these behaviors can be switched by modulating the pH value.
Single-crystal transition metal dichalcogenides (TMDs) and TMD-based heterojunctions have recently attracted significant research industrial interest owing to their intriguing optical electrical properties. However, the lack of a simple, low-cost, environmentally friendly, synthetic method poor understanding growth mechanism post huge challenge implementing TMDs in practical applications. In this work, we developed novel approach for direct formation high-quality, monolayer few-layer MoS2...