Two-dimensional (2D) sheets are currently in the spotlight of nanotechnology owing to high-performance device fabrication possibilities. Building a free-standing quantum sheet with controlled morphology is challenging when large planar geometry and ultranarrow thickness simultaneously concerned. Coalescence nanowires into single-crystalline promising approach leading large, molecularly thick 2D morphology. Here we report on bottom-up fabricate high-quality ultrathin single crystalline...

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...

Graphene quantum dots in powder form obtained single-step leads fabricating color tunable light emitting diodes with low turn-on voltages.

A generalization of the double sample holder (DSH) concept is presented for an ultra-high vacuum (UHV) low-temperature (LT) multi-probe scanning tunneling microscope (STM). In UHV, DSH carrying, side-by-side, a reference metal [Au(111) single crystal STM tip apex preparation] and ancillary stand-alone small (for samples originating from clean room) that can be mounted in situ in/out plate. navigation on both surfaces performed using UHV electron positioned above stage. For demonstration,...

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.

In-plane compressively strained α-Sn films have been theoretically predicted and experimentally proven to possess non-trivial electronic states of a 3D topological Dirac semimetal. The robustness these typically strongly depends on purity, homogeneity, stability the grown material itself. By developing reliable fabrication process, we were able grow pure InSb(100), without heating substrate during growth nor using any dopants. by molecular beam epitaxy, followed experimental verification...

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...

Monocomponent quantum dots (QDs) possess limited electron–hole delocalization capacity upon photoexcitation that suppresses the efficiency of photoenergy harvesting devices. Type II heterostructures offer band offsets at conduction and valence bands depending gaps constituent QDs which largely depend on their sizes. Hence, by keeping size one QD fixed while varying other selectively, interface can be engineered selectively. We report tuning synthesizing component modulated composed a sized...

Quaternary alloyed nanocrystals (NCs) composed of earth abundant, environment friendly elements are interest for energy-harvesting applications. These complex NCs useful as catalysts the degradation multiple refractory organic pollutants well nitro-organic reduction at a rapid rate. Here, remarkably fast (∼30 s) and facile synthesis crystalline quaternary chalcopyrite copper-zinc-iron-sulfide (CZIS) is reported. show excellent catalytic properties by degrading number dyes converting...

Topological insulators (TIs) are renowned for their exotic topological surface states (TSSs) that reside in the top atomic layers, and hence, detailed knowledge of layers is utmost importance. Here we present remarkable morphology changes Bi2Te3 surfaces, which have been freshly cleaved air, upon subsequent systematic annealing ultrahigh vacuum resulting effects on local area-averaging electronic properties states, investigated by combining scanning tunneling microscopy (STM), spectroscopy...

The pair breaking potential of individual magnetic impurities in s-wave superconductors generates localized states inside the superconducting gap commonly referred to as Yu- Shiba-Rusinov (YSR) whose isolated nature makes them ideal building blocks for artificial structures that may host Majorana fermions. One challenges this endeavor is understand their intrinsic lifetime, $\hbar/\Lambda$, which expected be limited by inelastic coupling with continuum thus leading decoherence. Here we use...

Investigating the electronic properties of a single ultra narrow semiconductor nanorod remains significant challenge in nanotechnology that may lead to miniaturization devices. We explore PbS using scanning tunneling microscopy and spectroscopy techniques. The spectroscopic an isolated self-assembled nanorods exhibit nonresonant electrons showed large tunnel current after exceeding certain critical bias voltage. A crossover from direct Fowler–Nordheim regime is observed voltage corresponding...

In nanoscale, gold is one of the widely studied metals. It well-known for its size dependent surface plasmonic absorbance. has also been reported that clusters a few atoms can show fluorescence. However, these optical properties are mostly associated with Au(0), and little explored compounds in nanoscale. Herein, we report new semiconducting nanocrystalline material involving Au(I), which shows intense, narrow, stable emission at bandedge absorption. These composed Au, Zn, S synthesized by...

We report on the synthesis of shape controlled ZnS nanocrystals designed into nanodots, nanorods, and nanowires retaining same diameter crystallographic phase. used UHV scanning tunneling microscopy spectroscopy to study rectification behavior from single nanocrystals. The nanorod nanowire show large current at negative bias in comparison positive demonstrating rectification, while nanodot shows symmetric current-voltage behavior. proposed a mechanism where direct is followed by resonant...

We report on the rectification properties from a single ZnS nanorod measured using UHV-SPM technique. The behavior is evidenced current–voltage characteristics nanorod. propose tunneling mechanism where direct dominant at lower applied bias voltages followed by resonant through discrete energy levels of A further increase in voltage changes to Fowler–Nordheim regime enabling behavior. Realizing may provide means realizing based miniaturized device.

We report on the synthesis of CdSe nanocrystal quantum dots (QDs) different radii (R). Size dependent optical properties like increase in confinement energy with decreasing radius for excitonic transitions are studied. Different calculated from second derivative UV-vis absorption spectra as synthesized QDs. The assigned to specific states by calculating transition energies using effective mass approximation. A close matching experiment suggesting that could provide a direct knowledge...

Probing electronic structure of metal–semiconductor heterostructures at the local scale is important both from fundamental and technological point views. Here, we report on nanoscale probing structures gold–lead sulfide nanodumbbells using ultra high-vacuum scanning tunneling microscopy spectroscopy techniques. A single lead nanorod shows delocalization conduction valence bands along length nanorod. The significantly altered upon formation metal contacts tips in form nanodumbbells....

The pair breaking potential of individual magnetic impurities in s-wave superconductors generates localized states inside the superconducting gap commonly referred to as Yu-Shiba-Rusinov (YSR) whose isolated nature makes them promising building blocks for artificial structures that may host Majorana fermions. One challenges this endeavor is understand their intrinsic lifetime, ℏ/Λ, which expected be limited by inelastic coupling with continuum thus leading decoherence. Here we use shot-noise...

Abstract Low electronic gap graphene nanoribbons (GNRs) are used for the fabrication of nanomaterial-based devices and, when isolated, mono-molecular electronics experiences, which a well-controlled length is crucial. Here, an on-surface chemistry protocol monitored producing long and well-isolated GNR molecular wires on Au(111) surface. The two-step Ullmann coupling reaction sequenced in temperature from 100 °C to 350 by steps 50 °C, returning at room between each step remaining ultrahigh...

Ultrasmall ZnS or PbS nanorods encapsulated in fluid-like soft organic surfactants show excellent miscibility the nematic liquid crystal (LC ZLI-4792) host resulting a novel matter type blend with enhanced electro-optic properties. The ultranarrow rods are of wurtzite phase and possess chemical bipolarity net dipole moment. centrosymmetric finite size shape dependent inherent moment despite their cubic rock-salt structure. When an electric field is applied, aligns along direction producing...

With a lateral bisnaphtho-extended chemical structure, finite 7-13 carbon atom wide armchair graphene nanoribbons (7-13-aGNRs) were on-surface synthesized. For all lengths up to

We investigated the topological insulator (TI) Bi2Te3 in four different environments (ambient, ultra-high vacuum (UHV), nitrogen gas and organic solvent environment) using scanning probe microscopy (SPM) techniques. Upon prolonged exposure to ambient conditions cleaved surface of pristine is observed be strongly modified during SPM measurements, while imaging freshly UHV shows considerably less changes surface. conclude that reduced stability upon triggered by adsorption molecular species...