A5082048729- 2D Materials and Applications
- MXene and MAX Phase Materials
- Perovskite Materials and Applications
- GaN-based semiconductor devices and materials
- Ga2O3 and related materials
- Radio Frequency Integrated Circuit Design
- Thermal Expansion and Ionic Conductivity
- Ferroelectric and Negative Capacitance Devices
- Silicon Carbide Semiconductor Technologies
- Photonic and Optical Devices
- Advanced Thermoelectric Materials and Devices
- Graphene research and applications
- Thermal properties of materials
- Semiconductor materials and devices
- Metal and Thin Film Mechanics
- Nanowire Synthesis and Applications
- ZnO doping and properties
- Semiconductor Lasers and Optical Devices
- Magnetic Properties and Synthesis of Ferrites
- Power Systems and Renewable Energy
- Metamaterials and Metasurfaces Applications
- Heusler alloys: electronic and magnetic properties
- Diamond and Carbon-based Materials Research
- Energy Harvesting in Wireless Networks
- Acoustic Wave Resonator Technologies
Boston University
2018-2023
University of British Columbia
2016-2018
University of Maryland, College Park
2017
Wuhan University of Technology
2009-2010
Abstract MXenes are emerging 2D materials with intriguing properties such as excellent stability and high conductivity. Here, a systematic study on the Raman spectra of α‐Mo 2 C (molybdenum carbide), promising member in MXene family, is conducted. Six experimentally observed modes from ultrathin crystal first assigned assistance phonon dispersion calculated density functional theory. Angle‐resolved polarized spectroscopy indicates anisotropy b – c plane. further used to unique domain...
Abstract PdSe 2 , an emerging 2D material with a novel anisotropic puckered pentagonal structure, has attracted growing interest due to its layer‐dependent electronic bandgap, high carrier mobility, and good air stability. Herein, detailed Raman spectroscopic study of few‐layer (two five layers) under the in‐plane uniaxial tensile strain up 3.33% is performed. Two prominent peaks are influenced differently depending on direction application. The mode redshifts more than when applied along...
MXenes are emerging members in the two-dimensional (2D) material family and highlighted by their high electrical conductivity. Among different MXenes, molybdenum-based especially molybdenum nitrides (MoNx), rarely accessible through common synthetic approach of selective etching due to absence stable MAX phase precursors. In this work, we apply atomic substitution synthesize two phases ultrathin nonlayered (i.e., Mo5N6 δ-MoN) from 1.6 42.9 nm thickness converting layered MoS2 under...
We report uniform layer-by-layer sublimation of black phosphorus under heating below 600 K. The uniformity and crystallinity BP samples after thermal thinning were confirmed by Raman spectra mapping. rate was around 0.18 nm min−1 at 500 K 1.15 550 Both room high temperature peak intensity ratio as functions thickness established for in situ determination control. Uniform crystalline 2 to 4-layer flakes with areas from 10 1000 μm2 prepared this method. No micron scale defects observed. method...
Strain-engineering band structure in transition-metal dichalcogenides (TMDC) is a promising avenue toward capabilities optoelectronics. For example, controlling the flow of optically generated quasiparticles can be achieved by localized strain field which reduces bandgap and generates an energy-band gradient that funnels neutral excitons to apex. It would even more advantageous mimic diode's internal field, where both conduction valence bands bend same direction, separate electrons holes....
Exciton localization through nanoscale strain has been used to create highly efficient single-photon emitters (SPEs) in 2D materials. However, the strong Coulomb interactions between excitons can lead nonradiative recombination exciton-exciton annihilation, negatively impacting SPE performance. Here, we investigate effect of on brightness, single photon purity, and operating temperatures strain-localized GaSe SPEs by using electrostatic doping. By gating charge neutrality point, annihilation...
Black phosphorus (BP), a layered material with puckered crystalline structure in each layer, has drawn intense interest due to its unique optical and electronic properties. In particular, the intricate Raman scattering effect BP is intriguing provides platform for researchers probe physical properties of depth. Here we report first observation anomalous modes frequency range 100–900 cm–1 resonant effect. The origin assignment are discussed based on excitation energy- angle-dependent...
The Bi-doped Mg2Si0.8Sn0.2 single phase compound is prepared by a solid state reaction (SSR)-spark plasma sintering (SPS) method. effect of the Bi content on thermoelectric properties mainly investigated. results show that obtained samples are sensitive to content. With increase in content, electrical conductivity (σ) and Seebeck coefficient (α) increased, while thermal (κ) decreased slightly between 300 K 850 K. When greater than 3.0 at%, sample shows maximum figure merit (ZT) value (1.17±0.05) at
The group-10 noble-metal dichalcogenides have recently emerged as a promising group of two-dimensional materials due to their unique crystal structures and fascinating physical properties. In this work, the resonance enhancement interlayer breathing mode (B1) intralayer Ag1 Ag3 modes in atomically thin pentagonal PdSe2 were studied using angle-resolved polarized Raman spectroscopy with 13 excitation wavelengths. Under energies 2.33, 2.38, 2.41 eV, intensities both low-frequency B1...
Nanoscale strain control of exciton funneling is an increasingly critical tool for the scalable production single photon emitters (SPEs) in two-dimensional materials. However, conventional far-field optical microscopies remain constrained spatial resolution by diffraction limit and thus can provide only a limited description nanoscale localization SPEs. Here, we quantify effects heterogeneous on energy brightness GaSe SPEs nanopillars with correlative cathodoluminescence, photoluminescence,...
We studied the stability and superconductivity of FeSe nanosheets during an in-air device fabrication process. Methods were developed to improve exfoliation yield maintain FeSe. Raman spectroscopy, atomic force microscopy, optical microscopy time-of-flight-secondary-ion-mass-spectroscopy measurements show that decayed in air. Precipitation Se particles iron oxidation likely occurred decay Transport revealed disappeared a conventional electron beam lithography Shadow mask evaporation transfer...
The d electron plays a significant role in determining and controlling the properties of magnetic materials. However, transitions, especially d–d emission, have rarely been observed materials due to forbidden selection rules. Here, we report an observation emission antiferromagnetic nickel phosphorus trisulfides (NiPS3) its strong enhancement by stacking it with monolayer tungsten disulfide (WS2). We attribute charge transfer between NiPS3 WS2 type-I heterostructure. peak splits into two...
Graphene is a promising materials platform for metasurface flat optics at terahertz wavelengths, with the important advantage of active tunability. Here we review recent work aimed development tunable graphene metasurfaces THz wavefront shaping (including beam-steering metamirrors and metalenses) light emission. Various design strategies constituent meta-units are presented, ranging from metallic phase-shifting elements combined nearby sheet tuning to plasmonic resonators providing required...
We investigated 10 to 200 nm thick black phosphorus flakes on SiO2/Si and polyimide substrates by Angle-resolved Polarized Raman spectra (ARPRS) using 442 excitation wavelength. The results revealed that ARPRS with can provide unambiguous, convenient, non-destructive fast determination of BP's crystallographic orientation. substrate thickness dependencies tensor elements were studied. These shown be influenced laser heating effect. By comparing in-situ measurements at elevated temperatures,...