Cesium lead halide (CsPbX3) nanocrystals have emerged as a new family of materials that can outperform the existing semiconductor due to their superb optical and charge-transport properties. However, lack robust method for producing quantum dots with controlled size high ensemble uniformity has been one major obstacles in exploring useful properties excitons zero-dimensional nanostructures CsPbX3. Here, we report synthesis approach enables precise control based on equilibrium rather than...

We report the direct hot-injection synthesis of Mn-doped cesium lead bromide (CsPbBr3) perovskite nanocrystals. In contrast to CsPbCl3 nanocrystals, where doping Mn under typical condition has been relatively straightforward, extending same approach CsPbBr3 very difficult. Here, we achieved nanocrystals via formation an intermediate structure (L2[Pb1–xMnx]Br4, L = ligand) before Cs precursor, which contains Mn–Br coordination present in A strong correlation was observed between luminescence...

Cesium lead halide (CsPbX3) perovskite nanocrystals (NCs) possess the unique capability of post-synthesis anion exchange providing facile tunability optical properties, which is usually achieved by mixing NCs with reactive precursors. In this work, we show that controllable can be in a dihalomethane solution CsPbX3 NC absence any spontaneously reacting source using photoexcitation as triggering mechanism for ion exchange. The reaction begins photoinduced electron transfer from to solvent...

Background Hyperuricemia is increasingly common in Southwestern China and poses significant health risks, including gout cardiovascular disease. Retinol intake has been hypothesized to affect uric acid levels, but this relationship remains unclear. Methods Data from 4,658 participants the Health Nutrition Survey (CHNS) 1991 2018 were analyzed. Dietary retinol was categorized using quantile-based methods, hyperuricemia identified as primary outcome. Logistic regression models used estimate...

To provide epoxy resin with crack healing capability, an containing both furan and epoxide groups, N,N-diglycidyl-furfurylamine (DGFA), was synthesized through a two-step approach. When it reacted N,N′-(4,4′-diphenylmethane) bismaleimide (DPMBMI) methylhexahydrophthalic anhydride (MHHPA), respectively, crosslinked polymer two types of intermonomer linkage yielded. That is, thermally reversible Diels–Alder (DA) bonds from the reaction between maleimide stable groups. In this way, cured DGFA...

Abstract To produce an epoxy resin with high intrinsic self‐healing efficiency, furfurylglycidyl ether (FGE) was synthesized following a two‐step route. It carried one furan and epoxide on each of its molecules. Having been cured using N , ′‐(4,4′‐diphenylmethane)bismaleimide methylhexahydrophthalic anhydride, FGE then polymerized two types intermonomer linkages. That is, thermally reversible Diels–Alder (DA) bonds from the reaction between maleimide groups, irreversible anhydride groups....

We report the strong light-induced activation of forbidden exciton transition in CsPbBr3 perovskite quantum dots mediated by symmetry-breaking polaron that modifies optical selection rule confined transition. The activated results an intense pump-induced absorption transient spectra above bandgap, where original parity-forbidden was located. In contrast to many other semiconductor dots, photoexcitation creates a sufficiently large perturbation via lattice-distorting polaron, which turns on...

Lead-halide perovskite nanocrystals (NCs) are receiving much attention as a potential high-quality source of photons due to their superior luminescence properties in comparison other semiconductor NCs. To date, research has focused mostly on NCs with little or no quantum confinement. Here, we measured the size- and temperature-dependent photoluminescence (PL) from strongly confined CsPbBr3 dots (QDs) highly uniform size distributions, examined factors determining evolution energy linewidth...

Nitrogen-doped lubricating additives have been proved to be an effective strategy improve the tribological properties of oil. However, traditional preparation methods nitrogen-doped defects including harsh conditions and a time-consuming process. Herein, we report method carbon dot (NCD) in short time by one-step aldehyde condensation reaction at room temperature. The small size effect nitrogen-containing functional groups NCD provide favorable for their dispersion low friction base...

Circularly polarized light (CPL) is a versatile tool to prepare chiral nanostructures, but the mechanism for inducing enantioselectivity not well understood. This work shows that energy and polarization of visible photons can initiate photodeposition at different sites on plasmonic nanocrystals. Here, CPL achiral gold bipyramids (AuBPs) creates hot holes oxidatively deposit PbO2 asymmetrically. We show first time location hence optical dissymmetry depends wavelength. Specifically, 488 532 nm...

Strong saturable absorption was observed in MoS2 nanoflowers, which were synthesized by a facile solvothermal method. A nanoflower-based absorber with high modulation depth of 51.8% and large intensity 275.5 GW cm−2 introduced to the application passively Q-switched fiber laser generation. Stable pulses at 1.56 μm low threshold power 16.10 mW, signal-to-noise ratio 52.5 dB short pulse duration 1.9 μs obtained. More importantly, output 3.10 mW related energy about 51.84 nJ can be attained...

ConspectusSemiconducting metal halide perovskite (MHP) nanocrystals have emerged as an important new class of materials the source photons and charges for various applications that can outperform many other semiconductor utilized same purposes. However, majority studies MHP focused on weakly or nonconfined systems, where quantum confinement giving rise to size-dependent confinement-enhanced photophysical properties cannot be explored readily. This was partially due challenge in producing...

Manganese ions were incorporated into CsPbX₃ nanocrystals with their morphology and size preserved using a photo-induced post-synthesis doping method.

A passively mode-locked Yb3+-doped fiber laser with a fundamental repetition rate of 5 GHz and wavelength tunable performance is demonstrated. piece heavily phosphate high net gain coefficient 5.7 dB/cm, in conjunction mirror by directly coating the SiO2/Ta2O5 dielectric films on ferrule exploited for shortening cavity to 2 cm. The oscillator has peak 1058.7 nm, pulse duration 2.6 ps, signal signal-to-noise ratio 90 dB. Moreover, found be continuously tuned from 1056.7 1060.9 nm increasing...

Based on a 1.8-cm-long heavily Tm3+-doped germanate fiber and being in-band-pumped by 1610 nm single-mode laser, high-efficiency high-power single-frequency distribute Bragg reflector (DBR) laser emitting at 1950 is demonstrated. The DBR has maximum output power of ~617 mW slope efficiency for the absorbed pump reaches to more than 42.2%. A stable single-longitudinal-mode with signal-to-noise ratio greater 63 dB realized. measured relative intensity-noise around -150 dB/Hz frequencies over...

Tm3+ doped lead silicate glasses with good thermal stability were prepared by the melt-quenching method. Based on absorption and emission spectra, Judd-Ofelt intensity parameters, cross sections, gain σe × FWHM calculated analyzed. These results suggest that are promising as mid-infrared laser materials. glass single mode (SM) fibers cladding diameter of 125 μm core 8.5 then fabricated rod-in-tube technique. The doping concentration reached high 4.545 1020 ions/cm3. ~2.0 amplified...

Fundamental repetition rates of 3.1 GHz, 7.0 and 12.5 GHz in passively modelocked Yb-doped fiber lasers are demonstrated. To the best our knowledge, fundamental rate is highest value for 1.0 μm mode-locked lasers. The oscillator has a peak wavelength 1047.5 nm pulse duration 1.9 ps. signal signal-to-noise ratio 57 dB. spectra gradually makes blue-shift threshold power increases with an increase rate. Furthermore, contrast to most all-normal-dispersion lasers, present linear resonator (e.g.,...

The fine structure of the band edge exciton and dark photoluminescence (PL) are topics significant interest in research semiconducting metal halide perovskite nanocrystals, with several conflicting reports on level ordering bright states accessibility emitting states. Recently, we observed intense PL strongly confined CsPbBr3 nanocrystals at cryogenic temperatures, contrast to weakly lacking PL, which was explained by confinement enhanced bright-dark splitting. In this work, investigated...

Because of the high synthesis cost, strong chemical inertness, complex process, and easy to endanger environment traditional carbon-based nanolubricant additives, development its application in lubrication is limited. Therefore, a new type lubricant additive with low yield, performance, environmental protection urgently needed. Herein, kilogram-scale carbon dots (CDs) was prepared by simple green one-step reaction aldol condensation, which showed excellent lubricating properties water...