A5081069948- Advanced Fluorescence Microscopy Techniques
- Near-Field Optical Microscopy
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Semiconductor Quantum Structures and Devices
- Photonic and Optical Devices
- Advanced Electron Microscopy Techniques and Applications
- Photoacoustic and Ultrasonic Imaging
- Organic and Molecular Conductors Research
- 2D Materials and Applications
- Optical Coherence Tomography Applications
- Nanocluster Synthesis and Applications
- Nanomaterials and Printing Technologies
- Neural Networks and Reservoir Computing
- Perovskite Materials and Applications
- Quantum Information and Cryptography
- Nanofabrication and Lithography Techniques
- Molecular Junctions and Nanostructures
- Integrated Circuits and Semiconductor Failure Analysis
- Nanowire Synthesis and Applications
- Advanced Optical Sensing Technologies
- Photonic Crystals and Applications
- Spectroscopy Techniques in Biomedical and Chemical Research
- Carbon and Quantum Dots Applications
- Advancements in Semiconductor Devices and Circuit Design
Center for Integrated Nanotechnologies
2018-2025
Los Alamos National Laboratory
2017-2025
Syracuse University
2014
Institute of Physics, Bhubaneshwar
2008
In van der Waals (vdW) heterostructures formed by stacking two monolayers of transition metal dichalcogenides, multiple exciton resonances with highly tunable properties are and subject to both vertical lateral confinement. We investigate how a unique control knob, the twist angle between monolayers, can be used dynamics. observe that interlayer lifetimes in MoSe2/WSe2 twisted bilayers (TBLs) change one order magnitude when is varied from 1° 3.5°. Using low-energy continuum model, we...
We demonstrate an important step toward on-chip integration of single-photon sources at room temperature. Excellent photon directionality is achieved with a hybrid metal-dielectric bullseye antenna, while back-excitation permitted by placement the emitter in subwavelength hole positioned its center. The unique design enables direct and very efficient front coupling emission either to low numerical aperture (NA) optics or directly optical fiber. To show versatility concept, we fabricate...
Tetramethyl-bis(ethylenedithio)-tetrathiafulvalene (TM-BEDT-TTF) enantiomers’ spin filtering and chiroptical properties are studied. Spin-filtering assessed by recording spin-polarized I – V curves (mc-AFM) of TM-BEDT-TTF fibrils.
One of the central aims field spintronics is control individual electron spins to effectively manage transmission quantized data. well-known mechanism for controlling electronic spin transport chiral-induced spin-selectivity (CISS) effect in which a helical nanostructure imparts preferential orientation on transport. potential application CISS as transduction pathway between and circularly polarized light within nonreciprocal photonic devices. In this work, we identify quantify degree...
Quantum dots (QDs) are steadily being implemented as down-conversion phosphors in market-ready display products to enhance color rendering, brightness, and energy efficiency. However, for adequate longevity, QDs must be encased a protective barrier that separates them from ambient oxygen humidity, device architectures designed avoid significant heating of the well direct contact between excitation source. In order increase utility technologies extend their usefulness more demanding...
Abstract Dip‐pen nanolithography (DPN) is used to precisely position core/thick‐shell (“giant”) quantum dots (gQDs; ≥10 nm in diameter) exclusively on top of silicon nanodisk antennas (≈500 diameter pillars with a height ≈200 nm), resulting periodic arrays hybrid nanostructures and demonstrating facile integration strategy toward next‐generation light sources. A three‐step reading‐inking‐writing approach employed, where atomic force microscopy (AFM) images the pre‐patterned substrate...
Abstract InP/CdSe core/thick‐shell “giant” quantum dots (gQDs) that exhibit blinking‐suppressed two‐color excitonic emission have been synthesized and optically characterized. These type II heterostructures photoluminescence from both a charge‐separated, near‐infrared state, shell‐localized visible‐color state. Infrared is intrinsic to the QD, while visible can either be eliminated or enhanced through chemical modification of InP surface prior CdSe shell growth. Single‐QD measurements...
Light-emitting nanocrystal quantum dots (QDs) are of high interest for use as down-conversion phosphors and direct emission sources in bulk solid-state devices reliable single photons information science. However, these materials prone to photooxidation that reduces the yield over time. Current commercial applications device architectures prevent oxidation without addressing underlying degradation reactions at level. To instead loss functionality by better synthetic engineering nanoscale...
Efficient, high rate photon sources with single-photon purity are essential ingredients for quantum technologies. Single-photon based on solid state emitters such as dots very advantageous integrated photonic circuits, but they can suffer from a two-photon emission probability, which in cases of noncryogenic environment cannot be spectrally filtered. Here we propose two temporal purification-by-heralding methods using process to yield highly pure and efficient emission, bypassing the...
Deterministic coupling between photonic nodes in a quantum network is an essential step toward implementing various technologies. The omnidirectionality of free-standing emitters, however, makes this highly inefficient, particular if the distant are coupled via low numerical aperture (NA) channels such as optical fibers. This limitation requires placing emitters nanoantennas that can direct photons into with very high efficiency. Moreover, to be able scale technologies large number channels,...
We report an optical imaging method that simultaneously achieves nanometer-scale spatial resolution and records single-photon arrival times with subnanosecond temporal resolution, allowing for visualization of nanoscale photoluminescence dynamics. The technique combines time-correlated counting single-molecule localization microscopy by monitoring the emission centroid location a 2 × array fibers are coupled to four detectors. applied this image isolated clustered CdSe/CdS core/shell quantum...
“Giant” or core/thick‐shell quantum dots (gQDs) are an important class of solid‐state emitter characterized by strongly suppressed blinking and photobleaching under ambient conditions, reduced nonradiative Auger processes. Together, these qualities provide distinguishing useful functionality as single‐ ensemble‐photon sources. For many applications, operation at elevated temperatures intense photon flux is desired, but performance dependent on the synthetic method employed for thick‐shell...
In this work we investigate the role that polytypism has on growth of multi-shelled, giant quantum dots (gQDs). Multi-shell was initiated at CdSe cores with either zinc blende or wurtzite crystal structures. The shells consisted a CdxZn1−xS gradient deposited in slow layer-by-layer SILAR process. final gQDs had sizes >15 nm, shapes and symmetry were influenced by core type, polytypic conditions. A study morphology structure change each stage shell carried out powder XRD, TEM, HRTEM,...
Time-resolved super-resolution microscopy was used in conjunction with scanning electron to image individual colloidal CdSe/CdS semiconductor quantum dots (QD) and QD dimers. The photoluminescence (PL) lifetimes, intensities, structural parameters were acquired nanometer scale spatial resolution sub-nanosecond time resolution. combination of these two techniques more powerful than either alone, enabling us resolve the PL properties QDs within dimers as they blinked on off, measure...
Simultaneous acquisition of emission intensity from two channels in dual-color fluorescence measurements can be used to determine the spectral properties an emitter. We detail a method extract quantitative information by considering models: single component model for peak wavelength determination and dual relative strength determination. The former is useful characterization establishing heterogeneity within emitter species, while latter analyzing energy transfer efficiency. Both models are...
Photoluminescence images can be acquired with detection schemes that have both single-photon sensitivity and nanosecond scale temporal resolution, enabling the study of possible structural bases for photoluminescence lifetimes other features photon arrival statistics. Within context super-resolution (SR) imaging, this has been demonstrated collect a bundle optical fibers are coupled to individual counting avalanche photodiode detectors. Recently, our group used four these "time-resolved...
We report on proof of principle measurements a concept for super-resolution imaging method that is based excitation field density-dependent lifetime modulation semiconductor nanocrystals. The prerequisite the technique access to nanocrystals with emission lifetimes depend intensity. Experimentally, requires confocal microscope fluorescence-lifetime measurement capability makes it easily accessible broad optical community. demonstrate single particle allows one achieve spatial resolution...
We fabricate several nanoantenna devices that enhance the directionality (over 80%) and emission rate (by a factor of 20) room-temperature quantum dot thus achieving single photon brightness enhancement over 1000.
A dual-color super-resolution microscope with polarization and orientation-resolving capabilities is presented. Combining single-molecule localization methods simultaneous measurements enables the determination of orientation single emitters, such as quantum dot nanocrystals, sub-10 nm precision. Additional spectral characterization particle emission allows capture multiple optical properties that impact energy transfer. We report on instrumentation development results from coupled clusters.
Nonblinking Giant Quantum Dots The functionally unique “giant” quantum dot—a nonblinking and nonphotobleaching room-temperature photon source—is the subject of numerous investigations its optical properties application demonstrations from 3D single-molecule tracking to light-emitting diodes. In article number 2300092, Jennifer A. Hollingsworth co-workers reveal explicit synthesis–structure–function correlations as a blueprint for designing syntheses produce nanoscale structures long-term...
We have investigated the formation of nanostructures on InP surfaces by utilizing 3keV Ar ions. The been studied as a function ion fluence and show variation in their size heights. surface roughness behavior also get modified. electronic structure investigation suggests that there is excess Indium surface, after irradiation, due to preferential sputtering Phosphorus atoms. In‐rich zones lead nucleation nanostructures.
In article number 1801503, Jennifer A. Hollingsworth and co-workers demonstrate an advance in nanofabrication using dip-pen nanolithography (DPN) to directly place nanocrystal quantum dots onto a three-dimensional nanostructured optical antenna. The results lay the groundwork for expanded use of DPN other scanning probe technologies additive preparation functional multi-component systems devices at nanoscale.
Quantum light and in particular single photons have become essential resources for a growing number of quantum applications including computing, key distribution metrology. Solid-state atomlike systems such as semiconductor dots color defects crystals the hallmark highly pure photon emitters past two decades. A interest has been developed nanocrystal (NQDs) centers diamond potential compact room-temperature emitters. There are however several challenges that inhibit use sources current...