A5074966716- 2D Materials and Applications
- Perovskite Materials and Applications
- Strong Light-Matter Interactions
- Quantum Dots Synthesis And Properties
- Graphene research and applications
- Organic and Molecular Conductors Research
- Quantum and electron transport phenomena
- Molecular Junctions and Nanostructures
- Chalcogenide Semiconductor Thin Films
- Thermal Radiation and Cooling Technologies
- Plasmonic and Surface Plasmon Research
- Mechanical and Optical Resonators
- MXene and MAX Phase Materials
- Iron-based superconductors research
- Electronic and Structural Properties of Oxides
- Semiconductor Quantum Structures and Devices
- Solid-state spectroscopy and crystallography
- Topological Materials and Phenomena
- Crystal Structures and Properties
- Surface and Thin Film Phenomena
- Photonic and Optical Devices
- Machine Learning in Materials Science
- Advanced Thermodynamics and Statistical Mechanics
- Nanocluster Synthesis and Applications
- ZnO doping and properties
Arizona State University
2019-2025
University of Arizona
2024-2025
University of California, Berkeley
2022
Tempe Union High School District
2020
The appearance of single photon sources in atomically thin semiconductors holds great promises for the development a flexible and ultracompact quantum technology which elastic strain engineering can be used to tailor their emission properties. Here, we show compact hybrid two-dimensional semiconductor-piezoelectric device that allows controlling energy photons emitted by emitters localized wrinkled WSe2 monolayers. We demonstrate fields exerted piezoelectric tune excitons up 18 meV...
The family of layered BiTeX (X = Cl, Br, I) compounds are intrinsic Janus semiconductors with giant Rashba-splitting and many exotic surface bulk physical properties. To date, studies on these materials required mechanical exfoliation from crystals which yielded thick sheets in nonscalable sizes. Here, we report epitaxial synthesis BiTeCl BiTeBr through a nanoconversion technique that can produce few triple layers Rashba (<10 nm) sapphire substrates. process starts van der Waals epitaxy...
We report the nanoscale conductivity imaging of correlated electronic states in angle-aligned WSe_{2}/WS_{2} heterostructures using microwave impedance microscopy. The noncontact probe allows us to observe Mott insulating state with one hole per moiré unit cell that persists for temperatures up 150 K, consistent other characterization techniques. In addition, we identify first time a at electron cell. Appreciable inhomogeneity is directly visualized heterobilayer region, indicative local...
van der Waals heterostructures composed of transition metal dichalcogenide monolayers (TMDCs) are characterized by their truly rich excitonic properties which determined structural, geometric, and electronic properties: In contrast to pure monolayers, electrons holes can be hosted in different materials, resulting highly tunable dipolar many-particle complexes. However, for genuine spatially indirect excitons, the nature is usually accompanied a notable quenching exciton oscillator strength....
The emergence of spatial and temporal coherence light emitted from solid-state systems is a fundamental phenomenon, rooting in plethora microscopic processes. It intrinsically aligned with the control light-matter coupling, canonical for laser oscillation. However, it also emerges superradiance multiple, phase-locked emitters, more recently, long-range order have been investigated bosonic condensates thermalized light, as well exciton-polaritons driven to ground state via stimulated...
Using time-resolved optical Kerr rotation, we measure the low temperature valley dynamics of resident electrons and holes in exfoliated WSe$_2$ monolayers as a systematic function carrier density. In an effort to reconcile many disparate timescales monolayer semiconductors reported date, directly compare doping-dependent relaxation two electrostatically-gated having different dielectric environments. fully-encapsulated structure (hBN/WSe$_2$/hBN, where hBN is hexagonal boron nitride), found...
Following the rise of interest in properties transition metal dichalcogenides, many experimental techniques were employed to research them. However, temperature dependencies optical transitions, especially those related band nesting, not analyzed detail for Here, we present successful studies utilizing photoreflectance method, which, due its derivative and absorption-like character, allows investigating direct transitions at high-symmetry point Brillouin zone nesting. By studying mentioned...
Engineering the properties of quantum materials via strong light-matter coupling is a compelling research direction with multiplicity modern applications. Those range from modifying charge transport in organic molecules, steering particle correlation and interactions, even controlling chemical reactions. Here, we study modification material demonstrate an effective inversion excitonic band-ordering monolayer WSe2 spin-forbidden, optically dark ground state. In our experiments, harness...
Abstract 2D Janus transition metal dichalcogenides (TMDs) have attracted attention due to their emergent properties arising from broken mirror symmetry and self‐driven polarization fields. While it has been proposed that vdW superlattices hold the key achieving superior in piezoelectricity photovoltaic, available synthesis ultimately limited realization. Here, first packed nanoscrolls made TMDs through a simple one‐drop solution technique are reported. The results, including ab initio...
Layered antiferromagnetic oxyhalides with high environmental stability have recently attracted significant interest owing to their applications in spintronics and quantum devices. These materials can sustain a host of interesting phenomena that arise from magnetic phase transitions associated structural changes. Although bulk crystal synthesis for some members this oxyhalide family has been previously reported, bottom-up approaches scalable growth remain limited. In work, we demonstrated the...
We investigated the formation of Schottky barriers at interface between rare-earth tritelluride (RTe3) crystals and n-type silicon (n-Si) substrates. This study explores rectifying characteristics RTe3/n-Si junctions (R = Dy, Ho, Er) their relation to charge density wave (CDW) transition. Using thermionic emission model, we analyzed current–voltage (I–V) measurements obtain barrier height (ϕSBH) ideality factor (η). The temperature dependence extracted ϕSBH η reveals kink features near CDW...
Abstract Recent studies have established Van der Waals (vdW) layered and 2D rare‐earth tritellurides (RTe 3 ) as superconductors near room‐temperature charge density wave (CDW) materials. Their environmental stability raises natural concern owing to aging/stability effects observed in other tellurium‐based crystals. Here, the results establish aging characteristics of these RTe systems involving a variety metals such La, Nd, Sm, Gd, Dy, Ho. The atomic force microscopy (AFM) scanning electron...
Atomically precise graphene nanoribbons (GNRs) synthesized from the bottom-up exhibit promising electronic properties for high-performance field-effect transistors (FETs). The feasibility of fabricating FETs with GNRs (GNRFETs) has been demonstrated, ongoing efforts aimed at further improving their performance. However, long-term stability and reliability remain unexplored, which is as important performance practical applications. In this work, we fabricated short-channel nine-atom-wide...
We demonstrate the synthesis of layered anisotropic semiconductor GeSe and GeSe2 nanomaterials through low temperature (∼400 °C) atmospheric pressure chemical vapor deposition using halide based precursors. Results show that GeI2 H2Se precursors successfully react in gas-phase nucleate on a variety target substrates including sapphire, Ge, GaAs, or HOPG. Layer-by-layer growth takes place after nucleation to form materials. Detailed SEM, EDS, XRD, Raman spectroscopy measurements together with...
Moiré superlattices in van der Waals (vdW) heterostructures form by stacking atomically thin layers on top of one another with a twist angle or lattice mismatch. The resulting moiré potential leads to strong modification the band structure, which can give rise exotic quantum phenomena ranging from correlated insulators and superconductors excitons Wigner crystals. Here, we demonstrate dynamic tuning WSe2/WS2 heterostructure at cryogenic temperature. We utilize optical fiber tip scanning...
Low-dimensional organic–inorganic hybrid perovskites have attracted much interest owing to their superior solar conversion performance, environmental stability, and excitonic properties compared three-dimensional (3D) counterparts. Among reduced-dimensional perovskites, guanidinium-based crystallize in layered one-dimensional (1D) two-dimensional (2D). Here, our studies demonstrate how the dimensionality of perovskite influences chemical physical under different pressures (i.e., bond...
Bosonic condensation and lasing of exciton polaritons in microcavities is a fascinating solid-state phenomenon. It provides versatile platform to study out-of-equilibrium many-body physics has recently appeared at the forefront quantum technologies. Here, we photon statistics via second-order temporal correlation function polariton emerging from an optical microcavity with embedded atomically thin MoSe_{2} crystal. Furthermore, investigate macroscopic phase transition for varying excitation...
Among many van der Waals materials rare-earth tritellurides (RTe3) allow studying several phenomena like magnetic, superconducting, and charge density wave (CDW). These studies show the effect of cationic alloying antiferromagnetic RTe3 for fully tunable near room-temperature CDW properties. DyxGd1−xTe3 DyxTb1−xTe3 alloys were synthesized through a chemical vapor transport technique, element composition was controlled by changing ratio metal reagents. The results that lattice parameters can...