In the realm of semiconductor nanomaterials, a crystal lattice heavily doped with cation/anion vacancies or ionized atomic impurities is considered to be general prerequisite accommodating excess free carriers that can support localized surface plasmon resonance (LSPR). Here, we demonstrate surfactant-assisted nonaqueous route anisotropic copper sulfide nanocrystals, selectively trapped in covellite phase, which exhibit intense, size-tunable LSPR at near-infrared wavelengths despite their...

We demonstrate that it is possible to convert CdSe nanocrystals of a given size, shape (either spherical or rod shaped), and crystal structure hexagonal wurtzite, i.e., close packed (hcp), cubic sphalerite, face-centered (fcc)), into ZnSe preserve all these characteristics the starting particles (i.e., shape, structure), via sequence two cation exchange reactions, namely, Cd2+ ⇒Cu+ ⇒Zn2+. When from wurtzite nanocrystals, with Cu+ yields Cu2Se in metastable phase, which we could follow...

CdSe nanocrystals of well-defined sizes (so-called magic-size clusters, MSCs) have been grown with progressively larger sizes. During the synthesis, relative populations different families MSCs vary, as smaller clusters evolve into clusters. The time evolution various (see figure) is modeled by taking account their much higher stability over any intermediate size. A blue-light-emitting diode based on these also presented.

Arranging anisotropic nanoparticles into ordered assemblies remains a challenging quest requiring innovative and ingenuous approaches. The variety of interactions present in colloidal solutions nonspherical inorganic nanocrystals can be exploited for this purpose. By tuning depletion attraction forces between hydrophobic nanorods semiconductors, dispersed an organic solvent, these could assembled 2D monolayers close-packed hexagonally arrays directly solution. Once formed, layers fished onto...

We investigate the relationship between structural and optical properties of organo-lead mixed halide perovskite films as a function crystallization mechanism. For methylammonium lead tri-iodide, organic cations rearrange within inorganic cage, moving from crystals grown in mesoporous scaffold to larger, oriented on flat substrate. This reduces strain felt by bonds forming cage affects motion cation it, influencing electronic transition at onset absorption spectrum semiconductor. Moreover,...

We report the synthesis, structural and optical characterization of CdSe/CdS/ZnS "double shell" nanorods their exploitation in cell labeling experiments. To synthesize such nanorods, first "dot-in-a-rod" CdSe(dot)/CdS(rod) core/shell nanocrystals were prepared. Then a ZnS shell was grown epitaxially over these CdSe/CdS which led to fluorescence quantum yield final core−shell−shell that could be as high 75%. The efficiency correlated with aspect ratio thickness around starting rods, varied...

A surfactant-assisted nonaqueous strategy, relying on high-temperature aminolysis of titanium carboxylate complexes, has been developed to access anisotropically shaped TiO2 nanocrystals selectively trapped in the metastable brookite phase. Judicious temporal manipulation precursor supply reaction mixture enables systematic tuning nanostructure geometric features over an exceptionally wide dimensional range (30−200 nm). Such degree control is rationalized within frame a self-regulated...

Silver and gold nanoparticles were synthesized by the sol–gel process in SiO 2 , TiO ZrO thin films. A versatile method, based on use of coordination chemistry, is presented for stabilizing Ag + Au 3+ ions systems. Various ligands metal tested, each system it was possible to find a suitable ligand capable preventing precipitation onto film surface. Thin films prepared spin‐coating glass or fused silica substrates then heat‐treated at various temperatures air H atmosphere nucleating...

We report a phosphine-free synthesis of p-type copper(I) selenide nanocrystals by colloidal approach in mixture oleylamine and 1-octadecene. The had cuboctahedral shape cubic berzelianite phase. Films these nonstoichiometric copper-deficient Cu2−xSe were highly conductive showed high absorption coefficient the near-infrared region. These could be used as hole-injection layers optoelectronic devices.

Shape- and phase-controlled ZnSe nanocrystals are synthesized in hot mixtures of long-chain alkylamines alkylphosphines. The variation the rate precursor addition, down to low controlled levels, allows nucleation, as well growth nanocrystals, switch between wurtzite zinc blend structures. Such a level control leads variety shapes, from spheres rods three-dimensional structures formed by rod sections interconnected through branching points. temperature- time-dependence chemical potentials for...

We report a general synthetic approach to tetrapod-shaped colloidal nanocrystals made of various combinations II-VI semiconductors. Uniform tetrapods were prepared using preformed seeds in the sphalerite structure, onto which arms grown by coinjection and chemical precursors into hot mixture surfactants. By this approach, wide variety core materials could be chosen (in practice, most semiconductors that phase, namely, CdSe, ZnTe, CdTe); contrast, best for arm growth CdS CdTe. The samples...

We describe an approach to synthesize colloidal nanocrystal heterodimers composed of CoPt3 and Au. The growth is based on the nucleation gold domains preformed nanocrystals. It a highly versatile methodology which allows us tune independently size two in each dimer by varying several reaction parameters. statistical analysis distribution domain sizes dimers compositional mapping achieved dark field imaging energy dispersive spectroscopy confirm that are indeed made Au, respectively....

A one-pot, two-step colloidal strategy to prepare bimagnetic hybrid nanocrystals (HNCs), comprising size-tuned fcc FePt and inverse spinel cubic iron oxide domains epitaxially arranged in a heterodimer configuration, is described. The HNCs have been synthesized unique surfactant environment by temperature-driven sequential reactions, involving the homogeneous nucleation of seeds subsequent heterogeneous growth oxide. This self-regulated mechanism offers high versatility control geometric...

Asymmetric binary nanocrystals (BNCs), comprising one c-axis elongated anatase TiO2 section and γ-Fe2O3 spherical domain attached together, are synthesized by heterogeneous nucleation of iron oxide onto the longitudinal facets nanorods in a ternary surfactant mixture. The topologically controlled composition BNCs is ascertained combination powder X-ray diffraction, Raman Mössbauer spectroscopy, high-angle annular dark-field imaging, high-resolution transmission electron microscopy lattice...

Colloidal semiconductor-magnetic hybrid nanocrystals with topologically controlled composition are fabricated by heterogeneous nucleation of spherical epsilon-Co domains onto anatase TiO2 nanorods. The latter can be selectively decorated at either their tips or multiple locations along longitudinal sidewalls, forming lattice-matched heterointerfaces regardless the metal deposition sites. possibility switching between heterostructure growth modes arises from facet-dependent chemical...

The surface passivation by organic ligands of differently composed cesium lead halide perovskite nanocrystals was explored.

A colloidal nonaqueous approach to semiconductor-magnetic hybrid nanocrystals (HNCs) with selectable heterodimer topologies and tunable geometric parameters is demonstrated. Brookite TiO(2) nanorods, distinguished by a curved shape-tapered profile richly faceted terminations, are exploited as substrate seeds onto which single spherical domain of inverse spinel iron oxide can be epitaxially grown at either one apex or any location along their longitudinal sidewalls in hot surfactant...

Herein, we report a colloidal wet-chemical approach enabling control on dopant concentration and location in nanocrystal host lattice. Growth-doping nucleation-doping, driven by primary tertiary amines, respectively, were identified as predominant doping mechanisms responsible for the introduction of nitrogen impurities interstitial substitutional sites highly branched rutile TiO2 nanostructures. High-resolution X-ray photoelectron spectroscopy was used to distinguish two occupational...

We report a low-temperature colloidal synthesis of single-layer, five-atom-thick, β-In2Se3 nanosheets with lateral sizes tunable from ∼300 to ∼900 nm, using short aminonitriles (dicyandiamide or cyanamide) as shape controlling agents. The phase and the monolayer nature were ascertained by analyzing intensity ratio between two diffraction peaks two-dimensional slabs various phases, determined simulations. These findings further backed-up comparing fitting experimental X-ray pattern Debye...

Suitable postsynthesis surface modification of lead-chalcogenide quantum dots (QDs) is crucial to enable their integration in photovoltaic devices. Here we exploit arenethiolate anions completely replace pristine oleate ligands on PbS QDs the solution phase, thus preserving colloidal stability and allowing solution-based processability into photoconductive thin films. Complete QD relies stronger acidic character arenethiols compared that alkanethiols demonstrated by FTIR UV–vis–NIR...

A new method for achieving high efficiency planar CH3NH3I3–xClx perovskite photovoltaics, based on a low pressure, reduced temperature vapor annealing is demonstrated. Heterojunction devices this hybrid halide exhibit top PCE of 16.8%, J–V hysteresis, and highly repeatable performance without need mesoporous or nanocrystalline metal oxide layer. Our findings demonstrate that large hysteresis not an inherent feature heterojunctions, efficient charge extraction can be achieved with uniform...

A colloidal crystal-splitting growth regime has been accessed, in which TiO(2) nanocrystals, selectively trapped the metastable anatase phase, can evolve to anisotropic shapes with tunable hyperbranched topologies over a broad size interval. The synthetic strategy relies on nonaqueous sol-gel route involving programmed activation of aminolysis and pyrolysis titanium carboxylate complexes hot surfactant media via simple multi-injection reactant delivery technique. Detailed investigations...

Biosystems integration into an organic field-effect transistor (OFET) structure is achieved by spin coating phospholipid or protein layers between the gate dielectric and semiconductor. An architecture directly interfacing supported biological to OFET channel proposed and, strikingly, both electronic properties biointerlayer functionality are fully retained. The platform bench tests involved OFETs integrating phospholipids bacteriorhodopsin exposed 1-5% anesthetic doses that reveal...

The Moore's law trajectory of hard x-ray spatial resolution extrapolates to a few nanometers within the next years, thereby promising critical space-resolved structural, electronic, and compositional nanoscale characterizations for wide variety materials. This review addresses capabilities advantages microbeam nanobeam techniques compared photon, electron, neutron, ion probes through selected applications including semiconductors, superconductors, metals, nanostructured devices.