Nitrogen-doped carbon quantum dots are synthesized by a one-step atmospheric pressure microplasma process. The origin of the observed photoluminescence emission and its relationship with nitrogen doping is studied using range optical chemical measurements along verification theoretical calculations. Nitrogen into core functionalization surface states oxygen groups gives rise to hybrid structure which responsible for luminescence yields up 33%. Carrier multiplication as step-like enhancement...

Single molecule devices provide a unique system to study the thermoelectric energy conversion at an atomistic level and can valuable information for design of organic materials. Here we present comprehensive transport properties molecular junctions based on C82, Gd@C82, Ce@C82. We combine precise scanning tunneling microscope break-junction measurements thermopower conductance with quantitatively accurate self-energy-corrected first-principles calculations. find that all three fullerene...

The knowledge of band edges in nanocrystals (NCs) and quantum-confined systems is important for alignment technologically significant applications such as water purification, decomposition organic compounds, splitting, solar cells. While the energy diagram bulk silicon carbides (SiCs) has been studied extensively decades, very little known about its evolution SiC NCs. Moreover, interplay between quantum confinement surface chemistry gives rise to unusual electronic properties remains barely...

Abstract The thermal transport properties of teflon (polytetrafluoroethylene) and its polyethylene counterparts are, while highly desirable widely used, only superficially understood. Here, we aim therefore to provide rigorous insight from an atomistic point view in context single-molecule devices. We show that for vinyl polymers adsorbed on metal-surfaces the strongly depends metal-molecule interface reduced conductance observed derivatives originates a phonon injection life time. In...

Highly stable and environmentally friendly nitrogen-doped graphite quantum dots consisting of ∼12 layers graphene, average diameter ∼7.3 nm, prepared by atmospheric pressure microplasma are reported to have blue emission due surface states created nitrogen doping (9 atomic%) reaction with oxygen. The low-temperature synthesis method requires simple precursors in water, no annealing or filtration, producing crystalline disc-shaped ∼68% photoluminescence yield at 420 nm excitation that shown...

Sn-cluster doping of Si nanocrystals represents a new approach to property tuning, which results in significant bandgap reduction and an atypical size-dependent behaviour, as confirmed by both experimental theoretical studies.

This study examines the effect of quantum confinement and surface orientations on electronic properties NiO dots. It compares nanocrystals produced via atmospheric-pressure microplasma femtosecond laser (fs-laser) ablation in water, finding that both methods yield quantum-confined with a defined face-centered cubic lattice. Notably, fs-laser synthesis generates crystalline from amorphous targets. While properties, i.e., energy highest occupied molecular orbital lowest unoccupied (LUMO),...

Carbon dots, or C-Dots, are graphitic particles below 10 nm that exhibit room temperature photoluminescence (PL). The specific PL mechanism of C-Dots varies with synthesis paths and remains unresolved. This study utilizes direct current microplasmas for reliable reproducible synthesis, exploring precursor outcomes the discharge current's impact on surface chemistry optical properties. nitrogen-doped (N-CQDs) synthesized display crystalline structures a core, nitrogen doping, functionalized...

In this work, we evaluated the feasibility of a paper-based bacterial detection system. The paper served as substrate for measurement electrodes and culture medium. Using printing technique, patterned gold onto applied Luria broth (LB) agar gel medium on top electrodes. As first step towards development system, determined changes in surface potential during growth monitored these over 24 h. This allowed us to correlate with different phases bacteria.

We discuss the electronic properties of quantum-confined nanocrystals. In particular, we show how, starting from discrete molecular states small nanocrystals, an approximate band structure (quasi-band structure) emerges with increasing particle size. Finite temperature is found to broaden in energy space forming even for nanocrystals quantum-confinement regime quasi-continuous bands k-space. This can be, a certain extend, interpreted along lines standard theory, while taking also finite size...

Abstract Water splitting is an essential process for converting light energy into easily storable in the form of hydrogen. As environmentally preferable catalysts, Cu‐based materials have attracted attention as water‐splitting catalysts. To enhance efficiency water splitting, a reaction should be developed. Single‐molecule junctions (SMJs) are attractive structures developing these reactions because molecule electronic state significantly modulated, and characteristic electromagnetic effects...

In this overview we discuss the electronic and optical properties of quantum-confined nanoparticles. particular, want to show what can learn from first-principles calculations, regarding influence size effects surface functionalization on nanoparticles demonstrate how be tailored. Here, are focusing sustainable materials, namely silicon-based with hydroxyl functionalization.

Abstract In this work, we benchmark non-idealities and variations in the two-dimensional graphene sheet. We have simulated more than two hundred graphene-based devices structure. distorted sheets included random, inhomogeneous, asymmetric out-of-plane surface corrugation in-plane deformation sheet through autocorrelation function non-equilibrium Green’s (NEGF) framework to introduce random distortion flat graphene. These effects inevitably appear due background substrate roughness or...

We study the optical and electronic properties of carbon-based quantum dots using first-principles calculations. Based on time-dependent density functional theory we calculated absorption emission carbon dots, focus influence surface (edge) groups. can show that nitrogen groups edges are decisive for small could give rise to charge-carrier multiplication which has been suggested by recent experiments. Moreover, explain stability, with regard in range, under ambient conditions. Here,...

Carbon dots (C-Dots) can be defined as spherical-like carbon particles (graphitic fragments) with sizes less than 10 nm. Typically, C-Dots exhibit ample room temperature photoluminescence (PL) whereby the PL properties of a well-defined crystalline core is related to size or conjugated domains accompany contribution from surface state, core, molecular configuration, and so on. However, up date exact mechanism origins depends on synthesis path remains unsettled [1-3]. In this we will...

Here we discuss the synthesis paths and optoelectronic properties in context of alpha tin (α-Sn) phase silicon/tin (SiSn) alloyed nanocrystals (NCs). We possibilities benefits stabilizing α-Sn larger sized by alloying with silicon. demonstrate that plasma-based processes allow stable elemental NCs also based SiSn quantum confinement size extraordinarily high Sn concentrations: i.e. fabricated confined plasma from femtosecond (fs) laser liquid media a concentration approximately 17%....

In article number 2008109, Marius Buerkle, Satoshi Kaneko, Tomoaki Nishino, and co-workers induce the water-splitting reaction under visible light utilizing a copper-based single-molecule junction. A product (hydrogen) reactant (water-molecule) are distinguished by measurements techniques based on conductance measurement, inelastic electron tunneling spectroscopy, first-principles calculations.

Abstract We discuss the electronic properties of quantum-confined nanocrystals. In particular, we show how, starting from discrete molecular states small nanocrystals, an approximate band structure (quasi-band structure) emerges with increasing particle size. Finite temperature is found to broaden in energy space forming even for nanocrystals quantum-confinement regime quasi-continuous bands k-space. This can be, a certain extend, interpreted along lines standard theory, while taking also...

We discuss the electronic and optical properties of semiconducting nanoparticles in quantum-confinement regime how they can be modeled accurately using first-principles calculations. address band-like features emerge from finite states with increasing particle size we control characteristics band structure by means surface chemistry alloying. In particular, are focusing on technological important issues such as bandgap engineering both magnitude well transition type (indirect vs. direct...