Materials Literature
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P- and/or B-doped Si nanocrystals (Si-ncs) embedded in glass matrices were studied by electron spin resonance (ESR) spectroscopy to investigate the origin of strong room-temperature photoluminescence (PL) of n- and p-type impurities codoped Si-ncs below the band-gap energy of bulk Si crystals. It was shown that the in…
The influence of a visible ${\text{Ar}}^{+}$-laser (488 nm) illumination on photoluminescence (PL) from ZnO nanocrystals excited by He-Cd laser (325 nm) at various excitation intensities and temperatures was investigated. A reversible quenching of the UV near-band-edge emission under ${\text{Ar}}^{+}$-laser illuminati…
Eu‐doped β‐SiAlON phosphor powders were prepared by a highly efficient combustion synthesis method. By adjusting the starting compositions and choosing appropriate reaction conditions, Si 6− z Al z O z N 8− z :Eu 2+ powders having z values ranging from 0.25 to 2.0 could be synthesized within a few minutes. Phase compo…
We report the effects of thermal annealing performed in N2 or O2 ambient at 1200°C on the structural and optical properties of Er silicate films having different compositions (Er2SiO5, Er2Si2O7, and their mixture). We demonstrate that the chemical composition of the stoichiometric films is preserved after the thermal…
Sr 1− x Ca x Bi 2 Nb 2 O 9 ( x =0, 0.2, 0.4, 0.6, 0.8 and 1) ceramics were prepared by a conventional solid‐state reaction method. Their dielectric and structural properties were investigated. X‐ray diffraction analysis indicated that single‐phase layered perovskites were obtained. For Ca‐substituted specimens, a diel…
The magnetic shape memory (MSM) effect was observed in Ni–Mn–Ga freestanding thin foils down to 90μm in thickness using top-down approach. The foils were prepared by thinning the bulk crystals exhibiting MSM effect. The effect was evaluated from the magnetization curves. The significant decrease in magnetic field need…
The microstructure, and dielectric and piezoelectric properties of the CeO 2 ‐modified potassium bismuth titanate K 0.5 Bi 4.5 Ti 4 O 15 (KBT) piezoelectric ceramics were investigated. X‐ray diffraction analysis revealed that the cerium‐modified KBT ceramics have a pure four‐layer Aurivillius‐type structure. The piezo…
Amyloid nanowires were incorporated in organic photovoltaic devices in order to enhance the transport properties. Amyloid fibrils act as a template for donor-acceptor materials. The current-voltage characteristics under illumination and in the dark display a maximum for the fill factor and the space charge limit curre…
The time-resolved photoluminescence of cyclodextrin-threaded conjugated molecular wires and their unthreaded analogues is studied to probe suppression of intermolecular interactions by supramolecular encapsulation. The polyrotaxane dynamics are exponential and independent of concentration, different from those of unth…
Tetrapod-like ZnS1−xSex alloy nanostructures (T-ZnS1−xSex) of different compositions (0 ≤ x ≤ 1) are synthesized by chemical vapor deposition. Their composition-dependent Raman scattering and cathodoluminescence are studied. The single-crystal T-ZnS1−xSex nanostructures exhibit strong and narrow near-band-edge emissio…
Al‐doped β‐SiC powders were synthesized via combustion reaction of the Si/C system in a 0.1 MPa nitrogen atmosphere, using polytetrafluoroethylene as the chemical activator and Al as the dopant. The β‐SiC powders produced have fine spherical particles and narrow particle size distribution. The impurity phase of Al 2 O…
ZnO nanowire arrays were grown on semi-insulating intrinsic GaAs substrates, and controlled arsenic-doping process was carried out to realize the n-ZnO∕p-ZnO nanowire array/GaAs structures. The constructed ZnO nanowire homojunctions demonstrated a clear rectifying behavior and the turn-on voltage was above 4.0V. The c…
Magnetoelectric coupling coefficient (α) values of 0.88mV∕cm∕Oe at 200Oe and magnetocapacitive effects are reported in solid-solution BF–LF–PT with large La substitution (50:50 in BF). Enhancement of magnetic, dielectric, and ferroelectric properties is also observed. The solid solution shows relaxor behavior with lar…
Asymmetric Schottky barriers between ZnO nanowire and metal electrode have been fabricated at the two ends of the nanowire. An obvious photocurrent generated from the device at zero voltage bias can be switched on/off with quick response by controlling the light irradiation. Moreover, the device can still afford a cur…
Polarizabilities (alpha), second-hyperpolarizabilities (gamma), and the gamma scaling factors (c) of polyynes [H-(C[triple bond]C)(n)-H, n = 1-8] were evaluated using the long-range corrected (LC) density functional theory (DFT) and LC-DFT with a short-range Gaussian attenuation (LCgau), as well as high quality wavefu…
Artificial photonic antenna systems have been realised by incorporating organic dyes into zeolite L. The size and aspect ratio of the cylindrically shaped zeolite crystals can be tuned over a wide range, adding to the versatility of this host material. A 600 nm sized crystal, for example, consists of about 96 000 one-…
Interior design: A 5 nm sized spherical complex, which confines 24 alkyl chains in its interior, provides a localized hydrophobic environment with a uniform size and structure (see picture; shell blue, Pd yellow, O red, C purple, H gray). The hydrophobic phase can solubilize dye molecules, and the hydrophobicity of th…
High temperature stability of Al-doped ZnO transparent thin films in air has been improved by a combination of optimized growth parameters and postgrowth treatment. Optical transparency was better than 90% for wavelengths ranging from 380 to at least 2500nm with films that also had resistivities of 2×10−4Ωcm. Dependin…
A recombinant protein, silaffin rSilC, adsorbed on a tailored polyelectrolyte surface is capable of initiating the nucleation and growth of 4 nm titania nanoparticles in a dispersed manner under ambient conditions. The approach presented here may be readily applicable to other organic and inorganic materials to enable…
A barrier-free bipolar diode (BFBD) and an ambipolar field-effect transistor (FET) are fabricated based on a doping-free carbon nanotube (CNT) CMOS inverter. The basic CNT device unit consists of two Pd and two Sc electrodes deposited side-by-side on a single CNT, and can be used as an n-FET, p-FET, CMOS inverter, and…