ZnO nanosheets (see Figure) are fabricated by a physical vapor-transport technique. Temperature-dependent microphotoluminescence spectroscopy is conducted from 80–857 K. A surprisingly strong high-temperature (857 K) photon emission observed. brief discussion given in an attempt to understand the mechanisms. Technically, this finding demonstrates that nanostructure has potential for optoelectronic applications.

Self-assembled zinc oxide (ZnO) and indium-doping (ZnO:In) nanorod thin films were synthesized on quartz substrates without catalyst in aqueous solution by sol-gel method. The samples characterized x-ray diffraction (XRD), scanning electron microscope (SEM), Raman-scattering spectroscopy, room-temperature photoluminescence (PL) spectra, temperature-dependent PL spectra measurements. XRD Raman illustrated that there no single In2O3 phase ZnO lattice after indium doping. of showed a strong UV...

Large-scale arrays of highly oriented single-crystal ZnO nanotubes (ZNTs) are successfully fabricated on transparent conductive substrates by a simple method from an aqueous solution at low temperature (typically 85°C). The tubular morphology the nanostructures is formed defect-selective chemical etching electrodeposited nanorods. size ZNT determined that nanorod which can be readily controlled tuning several electrodeposition parameters. present employed to prepare flexible, substrates, as...

ZnO p-n junction light-emitting diodes (LEDs) were fabricated on c-plane Al2O3 substrates by plasma-assisted molecular beam epitaxy. Gas mixture of N2 and O2 was used as the p-type dopant, which double-donor doping N2(O) can be avoided significantly. The layers have a higher hole density carrier mobility. LEDs showed very good rectification characteristic with low threshold voltage 4.0V even at temperature above 300K. emit intensive electroluminescence in blue-violet region 350K. emission...

Single-crystal squaraine dye nanowires are prepared on solid substrates by solvent evaporation. The can self-assemble into aligned arrays and patterns in parallel stripes. This simple one-step method for growth patterning of organic nanostructures would facilitate easy low-cost fabrication devices with one-dimensional nanostructures, especially the devices. Supporting information this article is available WWW under http://www.wiley-vch.de/contents/jc_2089/2008/adma200703142_s.pdf or from...

Undoped n-ZnO films have been deposited onto p-GaN to form a pn heterojunction, and the current−voltage curve of heterojunction shows obvious rectifying behaviors. A photodetector is fabricated from heterojunction. Under back-illumination conditions, GaN layer on one hand acts as p-type counterpart for layer, other "filter" that transparent illumination light with wavelength longer than 360 nm. Because "filter", narrow band-pass response only 17 nm in width. The results reported this paper...

Biaxial stress of ZnO film deposited on quartz was measured by side-inclination x-ray diffraction technique, indicating that the is subjected to a tensile stress. One part induced thermal mismatch between and increases with annealing temperature, while another results from lattice about 1.03GPa. The optical band gap shows blueshift increasing biaxial stress, opposed change for GaN. mechanism stress-dependent suggested in present work.

We demonstrate the bulk synthesis of single crystalline Cu-doped ZnO nanowires using (CuI+ZnI2) powders at 600 °C. These mass are characterized through x-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, transmission microscopy (TEM), selected area and high-resolution TEM; they have uniform diameters about 65 nm several tens microns in length. The growth ZnCuO is suggested for self-catalyzed vapour–liquid–solid. In particular, PL spectra these show emission peaks...

n-Type doping of CdSe nanowires is achieved by either co-evaporating indium at different temperatures during growth, or post-growth via a thermal diffusion process. The conductivity tuned reproducibly nearly five orders magnitude in controlled way, and carrier concentration as high ∼1019 cm−3 reached (see image). doped show sensitivity to light irradiation. Detailed facts importance specialist readers are published "Supporting Information". Such documents peer-reviewed, but not copy-edited...

The relationship between band gap and biaxial stress in wurtzite ZnO thin films has been investigated by side-inclination x-ray diffraction technique optical absorbance spectrum as well ab initio calculation. experimental result shows that differing from other semiconductor with hexagonal structure, such GaN, the of increases increase tensile stress. For explaining difference, calculation is performed to simulate GaN. calculated indicates under but GaN opposite, supporting our result. offset...

Broad band near-infrared (NIR) emitting phosphors activated with Cr3+ ions have great potential in a variety of applications. Microcrystalline barium gallate powders were synthesized and their phase structure, photoluminescence properties as well applications luminescence thermometer plant cultivation are investigated. It is revealed that Ba1.3Ga12O19.3: shows high efficiency NIR emission from 650 nm to 950 upon blue excitation. The dominated by narrow-peaks stem 2E→4A2 transition at 80 K,...

The shock wave/boundary layer interaction phenomenon in hypersonic inlets, affected by background waves, may induce the formation of multiple separation zones. Existing theories prove insufficient explaining underlying flow mechanisms behind complex phenomena arising from multi-separation zone interactions, which necessitates further investigation. To clarify governing factors this study developed a simplified dual-separation-zone model derived inlet field characteristics. A series numerical...

Bull's-eye! ZnS nanostructures consisting of three intersecting ribbons in the form a dart-shaped tricrystal were prepared by thermal evaporation powder. The have lengths several tens micrometers, growth direction [2], and width 0.5–1 μm (see SEM image). nanostructure is formed octahedral nucleation vapor–liquid–solid growth.

Well-aligned ZnO nanowire arrays have been successfully synthesized on Si(100) substrate by a vapour transport process. A thin film was used as the nucleation sites, which can control growth orientation of nanowires. By observation initial process growth, solid condensation mechanism proposed for in role to provide sites growth. It also found that density could be adjusted varying thickness film. The nanowires, had single-crystalline wurtzite structure, diameters 50–120 nm and lengths around...

Catalyst-free needle-like ZnO nanowires have been grown on Si(111) substrate at 430 °C via a simple solid–vapour process. The obtained are found to uniform size distribution with sharp tips. lengths of the range from 2.8 3.2 µm diameters about 100 nm for root and 30 tip parts. x-ray diffraction (XRD) result shows c-axis preferentially oriented. Transmission electron microscopy (TEM) selected area (SAED) analysis reveal that every single nanowire is well developed crystal. room temperature...

The optical and electrical properties of FeSe thin films are studied by both absorption Hall measurements, which suggest that ferromagnetic is a metal instead semiconductor. No gap observed in the whole spectrum range from far infrared to ultraviolet. Temperature dependent transport measurement indicates has resistivity about 10−3Ωcm. It also found there transition n-type conductivity at low temperatures p-type higher FeSe, attributed two-carrier nature thermal activation localized carriers film.

Nanoscaled coaxial materials with a periodically twinned ZnSe single crystal core and an amorphous silicon dioxide shell were synthesized by simple thermal evaporation process. As-fabricated ZnSe/SiO2 core/shell nanowires nanoribbons studied using scanning electron microscopy (SEM), transmission (TEM), selected area diffraction (SAED) pattern. The twinning period of about 10−30 nm has sphalerite structure common growth direction {11-1]. SiO2 thickness 5 nm. formation mechanism can be...

This work reports on the fabrication and characteristics of n-ZnO/p-GaN n-ZnO/n-MgZnO/n-ZnO/p-GaN heterojunction light emitting diodes (LEDs). Both devices exhibited diode-like rectifying current-voltage characteristics. Room temperature electroluminescence (EL) spectra for both LEDs consisted dominant emission at 375 nm two weaker bands centred 415 525 nm, which were attributed to ZnO excitonic transition defect-related emissions from GaN ZnO, respectively. Moreover, it was demonstrated...

We report on the fabrication of an n-Mg0.12Zn0.88O/p-GaN heterojunction light-emitting diode with MgO dielectric interlayer by plasma-assisted molecular beam epitaxy. The current−voltage curve showed obvious rectifying characteristics a threshold voltage about 8 V. Under forward bias, ultraviolet electroluminescence (EL) emission located at 374 nm coming from Mg0.12Zn0.88O layer was observed room temperature. This is one shortest EL emissions in ZnO-based pn junctions to best our knowledge....

High-quality ZnO nanocrystals have been fabricated by zinc ion implantation (160 keV, 1×1017 ions/cm2) into a CaF2(111) single-crystal substrate followed thermal annealing from 300 to 700 °C. X-ray diffraction results show that in (002) preferred orientation. The average grain size is ranging 14 19 nm corresponding the temperatures 500 A very strong ultraviolet near-band edge emission observed 372 379 nm. intensity enhanced and linewidth narrowed as temperature increases. commonly visible...

Temperature-dependent photoluminescence of MgZnO alloy film has been studied, and it is found that the emission intensity increases significantly at a certain temperature range then decreases when increasing further. The anomalous increase resulted from localized excitons in alloy, as revealed by enhanced second-order longitudinal optical phonon Raman spectrum film. A schematic model was suggested to depict carrier transportation process considering existence exciton states. results reported...

Photoluminescence and Raman scattering experiments were performed on Si/SiO2 superlattices grown by radio frequency magnetron sputtering Si, quartz glass substrates. Increasing the Si layer thickness in superlattice gave rise to an increased photoluminescence signal a signature for nanocrystalline Si. Annealing at 1000 °C nitrogen atmosphere also resulted significantly intensity that correlated with formation of superlattice. Relationships between emergence changes properties are discussed.