A binary ligand system composed of aliphatic carboxylic acids and primary amines various chain lengths is commonly employed in diverse synthesis methods for CsPbBr3 nanocrystals (NCs). In this work, we have carried out a systematic study examining how the concentration ligands (oleylamine oleic acid) resulting acidity (or basicity) affects hot-injection NCs. We devise general scheme cesium lead bromide NCs which allows control over size, size distribution, shape, phase (CsPbBr3 or Cs4PbBr6)...

Abstract Designing nanoscale components and units into functional defined systems materials has recently received attention as a nanoarchitectonics approach. In particular, exploration of in two-dimensions (2D) made great progress these days. Basically, 2D nanomaterials are center interest owing to the large surface areas suitable for variety active applications. The increasing demands alternative energy generation have significantly promoted rational design fabrication since discovery...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTColloidal Synthesis of Strongly Fluorescent CsPbBr3 Nanowires with Width Tunable down to the Quantum Confinement RegimeMuhammad Imran†§, Francesco Di Stasio†, Zhiya Dang†, Claudio Canale‡, Ali Hossain Khan†, Javad Shamsi†§, Rosaria Brescia†, Mirko Prato*†, and Liberato Manna*†View Author Information† †Nanochemistry ‡Nanophysics Departments, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy§ Dipartimento Chimica e...

Current colloidal synthesis methods for CdSe nanoplatelets (NPLs) routinely yield samples that emit, in discrete steps, from 460 to 550 nm. A significant challenge lies with obtaining thicker NPLs, further widen the emission range. This is at present typically achieved via atomic layer deposition onto cores, or by synthesizing NPL core/shell structures. Here, we demonstrate a novel reaction scheme, where start 4.5 monolayer (ML) NPLs and increase thickness two-step switches 2D 3D growth. The...

The lateral dimensions of CdSe nanoplatelets have a strong and unique influence on their opto-electronic properties, with sizes that can be tuned from the weak to exciton confinement regime. There are state-of-the-art reports several nanoplatelet syntheses; however, at present only thickness is well-controlled. We demonstrate here we achieve control over aspect ratio overall nanoplate area by carefully adjusting reagents induce in-plane growth. A variation fraction hydrated Cd(OAc)2 in...

In the past few years, several protocols have been reported on synthesis of CdSe nanoplatelets with narrow photoluminescence (PL) spectrum, high PL quantum efficiency, and short exciton lifetime. The corresponding core/shell are however still mostly based CdSe/CdS, which possess an extended lifetime a strong red shift band-edge absorption emission, in accordance quasi-type-II band alignment. Here we report robust procedure to grow ZnS shell around at moderate temperatures 100–150 °C, improve...

We report on the synthesis of silver (Ag)-doped CdSe nanoplatelets (NPLs) via postsynthesis cation exchange, using acetate as Ag precursor. High-resolution transmission electron microscopy and X-ray diffraction confirmed that NPLs maintain their morphology crystal structure after doping when executing exchange under reduced temperature in an ice bath. Spectroelectrochemistry transient absorption spectroscopy revealed Ag+ acts acceptor dopant. results emission is tunable from 609 to 880 nm,...

Abstract The technological challenge imposed by the time resolution essential to achieve real-time molecular imaging calls for a new generation of ultrafast detectors. In this contribution, we demonstrate that CdSe-based semiconductor nanoplatelets can be combined with standard scintillator technology 80 ps coincidence on hybrid functional pixel. This result contrasts fact overall detector light output is considerably affected loss index-light-guiding. Here, exploit principle 511 keV energy...

Artificial enzyme mimetics have attracted immense interest recently because natural enzymes undergo easy denaturation under environmental conditions restricting practical usefulness. We report for the first time chalcopyrite CuZnFeS (CZIS) alloyed nanocrystals (NCs) as novel biomimetic catalysts with efficient intrinsic peroxidase-like activity. Novel peroxidase activities of CZIS NCs been evaluated by catalytic oxidation substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in presence hydrogen...

We demonstrate ultrarapid interfacial formation of one-dimensional (1D) single-crystalline fullerene C60 nanorods at room temperature in 5 s. The ∼ 11 μm length and 215 nm diameter are developed a hexagonal close-pack crystal structure, contrary to the cubic structure pristine C60. Vibrational electronic spectroscopy provide strong evidence that van der Waals solid, as evidenced from preservation molecules within rods. Steady state optical reveals dominance charge transfer excitonic...

Colloidal two-dimensional (2D) nanoplatelet heterostructures are particularly interesting as they combine strong confinement of excitons in 2D materials with a wide range possible semiconductor junctions due to template-free, solution-based growth. Here, we present the synthesis ternary architecture consisting core CdSe, laterally encapsulated by type-I barrier CdS, and finally type-II outer layer CdTe so-called crown. The CdS acts tunneling between CdSe- CdTe-localized hole states, through...

Two dimensional (2D) colloidal PbS nanoplatelets (NPLs) with a thickness of 1.8–2.8 nm have been synthesized using single-molecule precursor approach lead octadecylxanthate. The lateral dimensions were tuned by varying the reaction temperature, growth time, and capping ligands. Transmission electron microscopy X-ray diffraction reveal that NPLs an orthorhombic crystal structure rather than rocksalt phase usually reported for bulk nanostructured PbS. 1.8 thickness, in combination tunable...

The typical synthesis protocol for blue-emitting CdSe nanoplatelets (NPLs) yields particles with extended lateral dimensions and large surface areas, resulting in NPLs poor photoluminescence quantum efficiency. We have developed a that achieves an improved control over the size, by exploiting series of long-chained carboxylate precursors vary from cadmium octanoate (C8) to stearate (C18). length this metallic precursor is key tune width aspect ratio final NPLs, shorter chain lengths, yield...

Colloidal semiconductor nanoplatelets exhibit strong quantum confinement for electrons and holes as well excitons in one dimension, while their in-plane motion is free. Because of the large dielectric contrast between its ligand environment, Coulomb interaction strongly enhanced. By means one- two-photon photoluminescence excitation spectroscopy, we measure energies 1S 1P exciton states CdSe with thicknesses varied from 3 up to 7 monolayers. comparison calculations, performed effective mass...

Colloidal CdTe nanoplatelets featuring a large absorption coefficient and ultrafast tunable luminescence coupled with heavy-metal-based composition present themselves as highly desirable candidates for radiation detection technologies. Historically, however, these have suffered from poor emission efficiency, hindering progress in exploring their technological potential. Here, we report the synthesis of possessing record efficiency 9%. This enables us to investigate fundamental photophysics...

Modulating the output of Nd : YAG laser sources has been evaluated as a technique for producing high quality welds in titanium alloys. Welds with internal were produced when square wave form was used modulation frequency ≥125 Hz and duty cycle 50%. Undercut present weld profile can be reduced if correct combination amplitude beam focal plane position are used. High speed observation subsequent Fourier analysis vapour plume keyhole behaviour have shown that they both exhibit same periodic...

For more than 10 years, the laser process has been studied for dismantling work; however, relatively few research works have addressed effect of high-power fiber cutting thick sections. Since in nuclear sector, a significant quantity material is required to be cut, this study aims improve reliability such work and indicates guidelines optimize procedure, particular, nozzle combinations (standoff distance focus position), minimize waste material. The results obtained show performance levels...

Two-dimensional (2D) materials with downscaled thicknesses are the quest of electronics industry because their immense potential in modern microelectronics. Despite discovery several novel 2D materials, flexible design high-performance free-standing ultrathin dielectric nanocrystals (NCs) a large planar morphology remains most challenging task. We develop method for synthesizing high-quality NCs PbS well-defined rectangular thickness ∼2 nm. The lateral size can be tuned up to few hundred...

Shape-controlled cobalt phosphide nanostructures have been synthesized using a one-pot reaction strategy for sensing volatile organic solvent molecules.

Abstract Formamidinium‐based perovskite solar cells (PSCs) present the maximum theoretical efficiency of lead family. However, formamidinium exhibits significant degradation in air. The surface chemistry PbS has been used to improve black phase stability. Here, use nanoplatelets with (100) preferential crystal orientation is reported, potentiate repercussion on growth grains and stability material consequently cells. As a result, vertical grains, stable current density 23 mA cm −2 , incident...

The exciton-phonon coupling has been studied in InxGa1−xN/GaN and GaN/AlxGa1−xN multiple quantum wells (MQWs) compared with that InxGa1−xN GaN epilayers. Phonon replicas up to four phonons can be well resolved only the alloy regions of MQWs (InxGa1−xN or AlxGa1−xN) was independent structure (well barrier), while no phonon exciton transitions were observed for free-exciton localized It thus suggests symmetry properties MQWs, which modifies dispersion relation, together disorder are...

We describe a simple route for designing ultranarrow PbS rods of 1.7 nm in diameter single step under bench-top reaction conditions. The are size controlled into 2.5 by tuning the temperature. Both nanorods exhibit molecule-like discrete narrow optical behavior with high fluorescence quantum yield. confinement owing to change is reflected absorption and photoluminescence spectroscopy. strength exciton–phonon coupling has been evaluated from Fröhlich Huang–Rhys parameter adiabatic...

Monodispersed bandgap tunable lead sulfide nanocrystals ranging from 0.6 to 1.7 eV have been synthesized by adjusting the reaction temperature and growth time. An evolution cuboctahedra perfect cube takes place at higher with longer annealing The absorb light both in visible IR spectral range. Bandgap dependent photovoltaic studies reveal optimal device performance for a critical size nanocrystal ∼1.2 revealing role of optimum on performance.

Dispersion of ultranarrow PbS nanorods 1.8 nm diameter, encapsulated by a fluidlike soft trioctylamine layer, in the nematic liquid crystal (LC ZLI-4792) results novel matter type blend with enhanced electro-optic properties. Despite having cubic rock-salt structure, rods possess finite inherent dipole moment and show excellent miscibility LC host. The local ordering significantly affects global allowing more rapid response These unique blends are obtainable only doping one-dimensional...