Publications

Showing 193 results for Author: Alexander A. Puretzky

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Sep, 2026

Journal

Enhancing Stability and Photoluminescence of Monolayer MoS2 by Encapsulation with Pulsed Laser Deposited Amorphous Boron Nitride

Monolayer two-dimensional (2D) materials offer exciting opportunities for next-generation microelectronics and optoelectronics, however, their sensitivity to environmental exposure and energetic plasma species requires the development of precise and damage-minimized methods for their device integration and protective encapsulation. Here, we demonstrate a pulsed laser depos…
Aug, 2026

Journal

Anticipating decoherence in quantum systems

Large-scale quantum technologies require coherence across distant nodes, necessitating indistinguishable quantum states. However, environmental disorder, including dephasing, spectral diffusion, and spin-bath interactions, undermines coherence. Using statistical methods, we uncover correlations in decoherence channels induced by slowly varying environments. Spectral diffus…
Jul, 2026

Journal

Spontaneous Polarization Suppression of Exciton–Exciton Annihilation in Rhombohedral-Stacked Bilayer Molybdenum Disulfide

Rapid exciton–exciton annihilation (EEA) in two-dimensional semiconductors limits access to high-density excitonic regimes essential for efficient optoelectronic operation under strong excitation. Here, we show that EEA is strongly suppressed in rhombohedral (3R)-stacked MoS2 bilayers relative to nonpolar 2H bilayers, and that this suppression is quantitatively consistent…
Jul, 2026

Journal

Synthetic Tuning of Exciton–Phonon Coupling in Janus WS2(1-x)Se2x Monolayers Revealed by Resonant Raman Excitation Spectroscopy for Optoelectronic Applications

Janus monolayers, such as WSSe, have broken out-of-plane symmetry and an intrinsic dipole moment, impacting exciton transport, lifetime, and phonon interactions while imbuing piezoelectric, photocatalytic, and Rashba spin-splitting properties to transition metal dichalcogenides (TMDs). The new properties of this atomically thin material can be used for optoelectronic devic…
May, 2026

Journal

Ultrafast exciton and trion dynamics in highly 𝑛-doped Mo⁢S2 monolayers: Many-body effects

Understanding many-body interactions of excitons and charge carriers in monolayer semiconductors is crucial for tuning their unique optical properties and optimizing their performance in optoelectronic devices. However, the sensitivity of these atomically-thin semiconductors to doping, defects, and strain – arising from synthesis, substrate, and environmental conditions –…
Mar, 2026

Journal

Substrate-Directed Underlayer Growth of Bilayer MoS2 Revealed by Mo Isotope Labeling

Direct control over the vertical formation sequence and stacking registry in van der Waals (vdW) bilayers is essential for device performance and moiré engineering yet difficult to resolve unambiguously with conventional probes. We use Mo isotope labeling in a two-step chemical vapor deposition process to synthesize bilayer MoS2 and trace its vertical formation on common s…
Dec, 2025

Journal

Nonequilibrium Synthesis of TiO2 Nanoparticle “Building Blocks” for Crystal Growth by Sequential Attachment in Pulsed Laser Deposition

Nonequilibrium growth pathways for crystalline nanostructures with metastable phases are demonstrated through the gas-phase formation, attachment, and crystallization of ultrasmall amorphous nanoparticles as building blocks in pulsed laser deposition (PLD). Temporally and spatially resolved gated-intensified charge couple device (ICCD) imaging and ion probe measurements ar…
Dec, 2025

Journal

Defect Engineering in Large-Scale CVD-Grown Hexagonal Boron Nitride: Formation, Spectroscopy, and Spin Relaxation Dynamics

Recently, numerous techniques have been reported for generating optically active defects in exfoliated hexagonal boron nitride (hBN), which hold transformative potential for quantum photonic devices. However, achieving on-demand generation of desirable defect types in scalable hBN films remains a significant challenge. Here, it is demonstrated that formation of negative bo…
Nov, 2025

Journal

Encapsulation of monolayer 2D materials using kinetic energy-controlled pulsed laser deposition

The integration of monolayer (ML) two-dimensional (2D) materials into next-generation microelectronics, optoelectronics, and sensors is hindered by their sensitivity to environmental exposure. Deposition of additional layers for encapsulation or growth on ML 2D materials by versatile but energetic plasma techniques such as pulsed laser deposition (PLD) has not been conside…
Sep, 2025

Journal

Growth of Carbon Nanotubes Using Mixed-Metal Catalysts That Include Heavy Refractory Metals as Catalyst Stabilizers

We report new findings from studies of a novel technique to augment the growth of CNTs. In this method, the catalytic metals used for CNT growth are combined with high-melting-point heavy refractory metals, which serve to stabilize the metal catalyst nanoparticles, from which the CNTs nucleate and grow. Our study investigates the combination of an iron catalyst with tungst…
Sep, 2025

Journal

Autonomous Multistate Nanoencoding Using Combinatorial Ferroelectric Closure Domains in BiFeO3

Recent advances in ferroic materials have identified topological defects as promising candidates for enabling additional functionalities in future electronic systems. The generation of stable and customizable polar topologies is needed to achieve multistates that enable beyond-binary device architectures. In this study, we show how to autonomously pattern on-demand highly…
Aug, 2025

Journal

Low energy implantation into transition metal dichalcogenide monolayers to form Janus structures

Atomically-thin two-dimensional (2D) materials face significant energy barriers for synthesis and processing into functional metastable phases such as Janus structures. Here, the controllable implantation of hyperthermal species from pulsed laser deposition (PLD) plasmas is introduced as a top-down method to compositionally engineer 2D monolayers. The kinetic energies of S…

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Publications

Enhancing Stability and Photoluminescence of Monolayer MoS2 by Encapsulation with Pulsed Laser Deposited Amorphous Boron Nitride

Anticipating decoherence in quantum systems

Spontaneous Polarization Suppression of Exciton–Exciton Annihilation in Rhombohedral-Stacked Bilayer Molybdenum Disulfide

Synthetic Tuning of Exciton–Phonon Coupling in Janus WS2(1-x)Se2x Monolayers Revealed by Resonant Raman Excitation Spectroscopy for Optoelectronic Applications

Ultrafast exciton and trion dynamics in highly 𝑛-doped Mo⁢S2 monolayers: Many-body effects

Substrate-Directed Underlayer Growth of Bilayer MoS2 Revealed by Mo Isotope Labeling

Nonequilibrium Synthesis of TiO2 Nanoparticle “Building Blocks” for Crystal Growth by Sequential Attachment in Pulsed Laser Deposition

Defect Engineering in Large-Scale CVD-Grown Hexagonal Boron Nitride: Formation, Spectroscopy, and Spin Relaxation Dynamics

Encapsulation of monolayer 2D materials using kinetic energy-controlled pulsed laser deposition

Growth of Carbon Nanotubes Using Mixed-Metal Catalysts That Include Heavy Refractory Metals as Catalyst Stabilizers

Autonomous Multistate Nanoencoding Using Combinatorial Ferroelectric Closure Domains in BiFeO3

Low energy implantation into transition metal dichalcogenide monolayers to form Janus structures