A bstract : Quantum‐dot cellular automata (QCA) is a scheme for molecular electronics in which information transmitted and processed through electrostatic interactions between charges an array of quantum dots. QCA wires, majority gates, clocked cell operation, (recently) true power gain cells has been demonstrated metal‐dot prototype system at cryogenic temperatures. Molecular offers very high device densities, low dissipation, ways to directly integrate sensors with logic memory elements....

We report a bottom-up synthesis of photochemically and thermally active azobenzene-based polyelectrolyte multilayer (PEM) planar defect embedded in colloidal photonic crystal (CPC). Both photoisomerization thermal cycling lead to precise tuning an intragap transmitting state induced by the PEM structural defect.

A straightforward and reproducible synthesis of crack-free large-area thin films 3D hexagonal (R-3m) mesostructured nanocrystalline titania (meso-nc-TiO2) using a Pluronic triblock copolymer (P123)/1-butanol templating system is described. The characterization the achieved combination electron microscopy (high-resolution scanning transmission microscopy), grazing-incidence small-angle X-ray scattering, in situ high-temperature diffraction, variable-angle spectroscopic ellipsometry....

The colloidal assembly of a nanoporous electrochromic 1D Bragg mirror comprising NiO and WO3 nanoparticle multilayers enables the convolution electrically tunable electronic crystals photonic into single device, providing thereby distinctive means creating manipulating color. We describe herein first example an (ECBM), combining made nanoparticles. Because are complementary in their coloration effects (e.g. cathodic for anodic NiO)1 corresponding change refractive index, tunability can be...

Reversible tuning of an intragap transmitting state induced by redox cycling is accomplished using a redox-active polyelectrolyte multilayer planar defect embedded in colloidal photonic crystal (CPC). The wavelength position the can be changed changing oxidation ferrocene moieties polymer backbone (see Figure). This could find applications electrochemically tunable microcavities and CPC-based laser sources.

In this work, we have used in situ spectroscopic ellipsometry to investigate the thickness-dependent dielectric functions of PtSe2, a transition metal dichalcogenide material that exhibits interesting optical and electrical properties. Continuous measurements were obtained while ∼25 nm-thick PtSe2 film was grown using molecular beam epitaxy. By Kramers–Kronig-consistent oscillators represent functions, fit spectra obtain function thickness during its entire growth cycle. The changes...

Biomolecules have been incorporated as designed planar defect layers in colloidal photonic crystals using self- assembly techniques (see figure). Through shifts of the intragap mode, for example, DNA conformational changes and enantioselective intercalation a chiral anticancer drug can be optically monitored. This newfound capability monitoring biochemistry bodes well development new generation simple on-the-spot color readout biosensors.

The mechanical properties of colloidal nanocrystal superlattices can be tailored through exposure to low-pressure plasma. elastic modulus and hardness the ligand-free 3.7 nm ZrO2 superlattice are found similar bulk yttria-stabilized tetragonal polycrystals same relative density but without any doping. As a service our authors readers, this journal provides supporting information supplied by authors. Such materials peer reviewed may re-organized for online delivery, not copy-edited or...

Accurate knowledge of optical constants (refractive index n and extinction coefficient k) ScN is crucial for understanding properties this binary nitride semiconductor as well its use in optoelectronic applications. Using spectroscopic ellipsometry a spectral range from far infrared to ultraviolet (0.045–8.5 eV), we determine k layers grown on Al2O3(0001) substrates by plasma-assisted molecular beam epitaxy. Fits data return the energies four oscillators representing critical points band...

Using a rotating analyzer spectroscopic ellipsometer, we have investigated the complex dielectric function of series ternary BexZn1−xTe thin films in energy range between 0.7 and 6.5 eV for alloy concentrations x=0.0 x=0.52. After determining using x-ray diffraction photoluminescence techniques, standard inversion technique was used to obtain optical constants from measured ellipsometric spectra. Analyzing second derivative both real imaginary parts constant, deduced critical point...

Inelastic light scattering from a single isolated silica sphere, of diameter as small 260nm, has been measured function sphere size by micro-Brillouin spectroscopy. The feasibility recording spectra sample tiny this, and for which only one particle is needed, further enhances the capabilities Brillouin powerful investigative tool. Such measurements afford evaluation elastic properties nanospheres determination polydispersity an aggregate particles asymmetric broadening its spectrum. Unlike...

Facile synthetic routes have been developed that provide access to cationic and anionic water-soluble polyferrocenylsilane (PFS) polyelectrolytes with controlled molecular weight narrow polydispersity. Living photolytic ring-opening polymerization of amino-functionalized [1]ferrocenophane (fc) monomers [fcSiMe{C[triple chemical bond]CCH(2)N(SiMe(2)CH(2))(2)}] (3), [fcSi{C[triple bond]CCH(2)N(SiMe(2)CH(2))(2)}(2)] (10), [fcSiMe(C[triple bond]CCH(2)NMe(2))] (14),...

Elastic constants of the recently grown nonequilibrium zinc-blende form MnTe were measured. Strained layer MnTe/ZnTe superlattices in which appears this studied using triple crystal x-ray diffraction. The diffraction spectra fitted a dynamical model to determine thickness and lattice each layer. From these other measurements, elastic ${\mathit{C}}_{11}$ ${\mathit{C}}_{12}$ determined be 2.22\ifmmode\pm\else\textpm\fi{}0.1 1.16\ifmmode\pm\else\textpm\fi{}0.1, respectively. These values are...

This article has two objectives. First, we determine the indices of refraction n a series molecular beam epitaxy-grown Zn1−xCdxSe epilayers using technique based on coupling evanescent waves via prism into semiconductor film. Highly precise values n, and their dependence alloy composition x, are obtained for photon energies below band gap material. And second, use these results to demonstrate usefulness coupler method as very reliable, convenient, accurate tool simultaneous determination...

This article investigates distributed Bragg reflectors (DBRs) based on two wide-gap II–VI semiconductor alloy combinations: ZnMgSe/ZnCdSe and ZnMgSe/ZnSeTe. Prior to fabrication of the DBRs, a prism coupler technique was used determine indices refraction n above ternary alloys various compositions prepared by molecular beam epitaxy (MBE). Using these values n, DBR systems, Zn0.66Mg0.34Se/Zn0.74Cd0.20Se Zn0.62Mg0.38Se/ZnSe0.56Te0.44, were fabricated, each with relatively large difference in...

We report pseudodielectric function data 〈ε〉=〈ε1〉+i〈ε2〉 of Zn1−xMgxSe and Zn1−xBexSe samples grown on GaAs substrates. The were obtained from 1.5 to 6.0 eV using spectroscopic ellipsometry. Critical point parameters by fitting model line shapes numerically calculated second energy derivatives 〈ε〉, which the bowing spin-orbit-splitting Δ1 E1 E1+Δ1 gaps obtained. A transfer oscillator strength with increasing Mg Be composition a positive these threshold energies are attributed k-linear...

Using a combination of first-principles molecular dynamics and conventional electronic-structure calculational methods, we examine the pronounced bowing phenomenon, which characterizes direct energy gap ${E}_{g}^{\ensuremath{\Gamma}}$ in ${\mathrm{ZnSe}}_{1\ensuremath{-}x}{\mathrm{Te}}_{x}$ alloys. The is found to be attributable significant electronegativity difference between two anions. We also structure sinusoidally modulated superlattices whose composition varies range...

A program to enhance the teaching of nanoscience concepts in multiple pedagogical contexts at Kenyon College, Gambier, OH, is described. In an introductory physics laboratory course, students use a Veeco model CP-II scanning probe microscope image optical diffraction grating. The results survey student reaction their experience are reported as faculty assessment exercise. Use by senior-level advanced course also detailed. novel first-year seminar described, including experiment on...

This paper describes the creation of mesoporous inorganic films based on plasma processing ligand-capped nanocrystals. We use nanorods HfO2 as a model system and report an extensive characterization chemistry, structure, mechanical properties, reactivity to show that (i) aspect ratio regulates pore size volume in predictable manner yields increase porosity over spherical nanocrystals up 60%, (ii) modulus (>25 GPa) hardness (>1.1 are sufficient tolerate chemical–mechanical planarization,...

We have measured the wavelength dependence of indices refraction n epitaxial Zn1−xMgxSe and Zn1−xCdxSe films for a series alloy compositions x, at wavelengths below energy gaps these semiconductor alloys. The measurements were performed using combination prism coupler method reflectivity. technique was capable measuring with an accuracy least 0.1% four discrete wavelengths, simultaneously to determine thickness layers uncertainty less than 0.5%. Using discrete, highly precise values n,...