The ability to perform optical sectioning is one of the great advantages laser-scanning microscopy. This introduces, however, a number difficulties due scanning process, such as lower frame rates serial acquisition process. Here we show that by introducing spatiotemporal pulse shaping techniques multiphoton microscopy it possible obtain full-frame depth resolved imaging completely without scanning. Our method relies on temporal focusing illumination pulse. pulsed excitation field compressed...

Significance Halide perovskite (HaP) semiconductors are revolutionizing the field of photovoltaic (PV) solar energy conversion by showing remarkable performance cells made with HaPs. “Ferroelectrics” is one frequently suggested reason because it may allow spatial separation flow electrons from where they were generated (holes). Unlike common, electrically insulating, ferroelectric materials, HaPs [especially tetragonal methylammonium lead triiodide (MAPbI 3 )] semiconducting, and to find out...

Despite the recent surge of interest in lead halide perovskite nanocrystals, there are still significant gaps understanding nucleation and growth processes involved their formation. Using CsPbX3 as a model system, we systematically study formation mechanism cubic via oriented attachment into larger nanostructures, associated phase transformations. We found evidence to support that NCs occurs through seed-mediated method, where Pb° NPs formed during course reaction act seeds. Further...

Self-healing, where a modification in some parameter is reversed with time without any external intervention, one of the particularly interesting properties halide perovskites. While there are number studies showing such self-healing perovskites, they all carried out on thin films, interface between perovskite and another phase (including ambient) often dominating interfering factor process. Here, (methylammonium, formamidinium, cesium lead bromide (MAPbBr3 , FAPbBr3 CsPbBr3 )) single...

Active control over the shape, composition, and crystalline habit of nanocrystals has long been a goal. Various methods have shown to enable postsynthesis modification nanoparticles, including use Kirkendall effect, galvanic replacement, cation or anion exchange, all taking advantage enhanced solid-state diffusion on nanoscale. In these processes, however, alteration nanoparticles requires introduction new precursor materials. Here we show that for cesium lead halide perovskite reversible...

Circular dichroism (CD) induced at exciton transitions by chiral ligands attached to single component and core/shell colloidal quantum dots (QDs) was used study the interactions between QDs their capping ligands. Analysis of CD line shapes CdSe CdS capped with l-cysteine reveals that all features in complex spectra can be assigned different excitonic transitions. It is shown each transition accompanied a derivative shape response, indicating ligand split level into two new sublevels,...

ConspectusThe rediscovery of the halide perovskite class compounds and, in particular, organic and inorganic lead (LHP) materials lead-free derivatives has reached remarkable landmarks numerous applications. First among these is field photovoltaics, which at core today's environmental sustainability efforts. Indeed, efforts have born fruit, reaching to date a power conversion efficiency 25.2% for double-cation Cs, FA thin film device. Other applications include light particle detectors as...

Photoisomerization of azobenzenes from their stable E isomer to the metastable Z state is basis numerous applications these molecules. However, this reaction typically requires ultraviolet light, which limits applicability. In study, we introduce disequilibration by sensitization under confinement (DESC), a supramolecular approach induce E-to-Z isomerization using light desired color, including red. DESC relies on combination macrocyclic host and photosensitizer, act together selectively...

Phase-and-polarization coherent control is applied to the nonlinear response of a quantum system. We use it obtain high-resolution background-free single-pulse anti-Stokes Raman spectra. The ability both spectral phase and polarization enables measurement specific off-diagonal susceptibility tensor element while exploiting different resonant signal nonresonant background achieve maximal suppression.

The late-time nonlinear evolution of the three-dimensional (3D) Rayleigh–Taylor (RT) and Richtmyer–Meshkov (RM) instabilities for random initial perturbations is investigated. Using full 3D numerical simulations, a statistical mechanics bubble-competition model, Layzer-type drag-buoyancy it shown that RT scaling parameters, αB αS, are similar in two three dimensions, but RM exponents, θB θS lower by factor 2 dimensions. similarity parameter hB/〈λ〉 higher 3 case compared to 2D case, very good...

A novel method for detection of noble-metal nanoparticles by their nonlinear optical properties is presented and applied specific labeling cellular organelles. When illuminated laser light in resonance with plasmon frequency these generate an enhanced multiphoton signal. This signal measured to obtain a depth-resolved image scanning microscope setup. Plasmon-resonance images both live fixed cells, showing organelles membranes, either two-photon autofluorescence or third-harmonic generation,...

The spectroscopy and dynamics of multiple excitations on colloidal type-II $\mathrm{Cd}\mathrm{Te}∕\mathrm{Cd}\mathrm{Se}$ core-shell quantum dots (QDs) are explored via quasi-cw multiexciton spectroscopy. charge separation induced by the band offset redshifts exciton emission increases radiative lifetime. In addition, we observe a significant modification properties compared with core-only or type-I QDs. particular, Auger recombination lifetimes significantly increased, up to nanosecond...

A new design of dye-sensitized solar cells involves colloidal semiconductor quantum dots that serve as antennas, funneling absorbed light to the charge separating dye molecules via nonradiative energy transfer. The dot donors are incorporated into solid titania electrode resulting in high transfer efficiency and significant improvement cell stability. This practically separates processes absorption carrier injection, enabling us optimize each these separately. Incident photon-to-current...

Carrier (exciton) multiplication in colloidal InAs/CdSe/ZnSe core−shell quantum dots (QDs) is investigated using terahertz time-domain spectroscopy, time-resolved transient absorption, and quasi-continuous wave excitation spectroscopy. For by high-energy photons (∼2.7 times the band gap energy), highly efficient carrier (CM) results appearance of multi-excitons, amounting to ∼1.6 excitons per absorbed photon. Multi-exciton recombination occurs within tens picoseconds via Auger-type...

Abstract The fresh water fish neon tetra has the ability to change structural color of its lateral stripe in response a light conditions, from blue‐green light‐adapted state indigo dark‐adapted state. colors are produced by constructive interference reflected stacks intracellular guanine crystals, forming tunable photonic crystal arrays. We have used micro X‐ray diffraction track time distinct spots corresponding individual arrays within single cell during change. demonstrate that reversible...

The observed intermittent light emission from colloidal semiconductor nanocrystals has long been associated with Auger recombination assisted quenching. We test this view by observing transient dynamics of CdSe/CdS/ZnS using time-resolved photon counting. size and intensity dependence the decay seem inconsistent those expected processes. Rather, data suggest that in "off" state quantum dot cycles a three-step process: photoexcitation, rapid trapping, subsequent slow nonradiative decay.

We present a geometrical representation of the process sum frequency generation in undepleted pump approximation, analogy with known optical Bloch equations. use this to propose technique for achieving both high efficiency and large bandwidth conversion using adiabatic inversion scheme. The is analogous rapid passage NMR, constraints are derived context. This scheme realized experimentally an aperiodically poled potassium titanyl phosphate (KTP) device, where we achieved signal-to-idler over...

Multiphoton excitation by temporally focused pulses can be combined with spatial Fourier-transform pulse shaping techniques to enhance control of the volume.Here we propose and demonstrate an optical system for generation such spatiotemporally engineered light using a combination twodimensional reconfigurable modulator, dispersive setup temporal focusing.We show that although properties holographic beam significantly differ from those plane-wave illumination used in previous focusing...

The optical diffraction limit imposes a bound on imaging resolution in classical optics. Over the last twenty years, many theoretical schemes have been presented for overcoming barrier using quantum properties of light. Here, we demonstrate superresolution method taking advantage nonclassical light naturally produced fluorescence microscopy due to photon antibunching, fundamentally phenomenon inhibiting simultaneous emission multiple photons. Using counting digital camera, detect...

Abstract Biological photonic systems composed of anhydrous guanine crystals evolved separately in several taxonomic groups. Here, two such found fish and spiders, both which make use crystal plates to produce structural colors, are examined. Measurements the photonic‐crystal structures using cryo‐SEM show that skin spider integument ∼20‐nm thick. The reflective unit comprises stacks single alternating with ∼230‐nm‐thick cytoplasm layers. In spiders formed as doublet crystals, cemented by...

Abstract In this study, a facile and effective approach to synthesize high‐quality perovskite‐quantum dots (QDs) hybrid film is demonstrated, which dramatically improves the photovoltaic performance of perovskite solar cell (PSC). Adding PbS QDs into CH 3 NH PbI (MAPbI ) precursor form QD‐in‐perovskite structure found be beneficial for crystallization perovskite, revealed by enlarged grain size, reduced fragmentized grains, enhanced characteristic peak intensity, large percentage (220) plane...

We measured the quantum-confined Stark effect (QCSE) of several types fluorescent colloidal semiconductor quantum dots and nanorods at single molecule level room temperature. These measurements demonstrate possible utility these nanoparticles for local electric field (voltage) sensing on nanoscale. Here we show that charge separation across one (or more) heterostructure interface(s) with type-II band alignment (and associated induced dipole) is crucial an enhanced QCSE. To further gain...

Whenever several quantum light emitters are brought in proximity with one another, their interaction common electromagnetic fields couples them, giving rise to cooperative shifts resonance frequency. Such collective line central modern atomic physics, being closely related superradiance on hand and the Lamb shift other. Although have been theoretically predicted more than fifty years ago, effect has not observed yet a controllable system of few isolated emitters. Here, we report direct...