共查询到20条相似文献,搜索用时 31 毫秒
1.
近年来,有机发光二极管(OLED)被广泛应用于智能手机等中小尺寸显示屏,并逐步进入电视等大尺寸显示领域和照明市场。随着OLED平板显示新时代的到来,对显示屏的彩色化与图案化研究提出了更高要求。与传统真空蒸镀技术相比,喷墨打印技术更容易实现大面积器件的彩色化和复合功能材料的图案化,且工艺简单,成本低廉,并可进行柔性器件加工。本文综述了采用喷墨打印技术制备OLED显示屏的研究现状,并系统介绍了喷墨打印设备的发展历程,通过优化bank结构提高显示屏的分辨率,优化墨水配方及组成配比抑制喷墨液滴的“咖啡环”效应,从而提高显示器发光均匀性,最后对国内外该技术产业进行了概述与展望。 相似文献
2.
Deeder M. Aurongzeb 《Solid State Communications》2005,134(3):165-169
Effect of temperature and surface tension on surface during sedimentation is studied using atomic force microscopy. Effects of surface tension is incorporated by using ∼1 mm radius water droplets. Surface tension of water droplet directed the deposition of dissolved particles around the perimeter of the droplet; leaving almost hollow circle in the middle with light deposition due to the particles being close to the surface. Evaporating shallow water solutions left random salt structures on the surface. Growth exponents are calculated along with the fractal dimension. For sedimentation process in shallow water (depth of ∼2 mm), a transition is observed from continuum model (1.88±0.2) to KPZ (0.406±0.082) universality class around ∼1 μm at room temperature. For droplets evaporation, turbulent (multi-affine) to self-affine transition is observed. Fractal dimensions (FD) for the droplets are found to be between one and two. The FD values are consistent with the fact that competing nonlinear terms are present in the system. 相似文献
3.
Jinjun Liu 《Journal of Molecular Spectroscopy》2009,256(1):111-19012
Widely tunable, Fourier-transform-limited pulses of terahertz (THz) radiation have been generated using (i) crystals of the highly nonlinear organic salt 4-N,N-dimethylamino-4′-N′-methyl stilbazolium tosylate (DAST), (ii) zinc telluride (ZnTe) crystals, (iii) gallium phosphide (GaP) crystals, and (iv) low-temperature-grown gallium arsenide (LTG-GaAs) photomixers with THz spiral antennas. Outputs from two narrowband (Δν < 1 MHz, λ ∼ 800 nm) cw titanium-doped sapphire (Ti:Sa) ring lasers with a well-controlled frequency difference were shaped into pulses using acousto-optic modulators (AOM), coupled into an optical fiber, pulse amplified in Nd:YAG-pumped Ti:Sa crystals and used as optical sources to pump the THz emitters. The THz radiation was detected over a broad frequency range and its bandwidth was determined to be ∼10 MHz. The spectroscopic potential of the THz source is illustrated by the absorption spectrum of a pure rotational transition of OCS. 相似文献
4.
Two large and complex adsorbed organic molecules, coronene (C24H12) and C60, have been used to produce Si dimer vacancy defects on Si(0 0 1) by thermal decomposition. Studies by STM show that the aligned structural arrangement of the dimer vacancy defects produced is independent of the chemical structure of the organic molecules. This indicates that the chemistry of the thermally decomposed carbon species produced by decomposition of the organic molecule controls the organization of the Si dimer vacancy defects. It is found that ∼1 C atom is responsible for each dimer vacancy defect for both molecules in accordance with earlier studies of C2H2 decomposition on Si(0 0 1). 相似文献
5.
Influence of particle size and compaction pressure on the magnetic properties of iron-phenolic soft magnetic composites 总被引:1,自引:0,他引:1
This paper investigates the effect of particle size and compaction pressure on the magnetic properties of iron-phenolic soft magnetic composites (50 Hz-1000 kHz). The results showed that the optimum amount of phenolic resin to attain maximum permeability and minimum loss factor at 10 kHz is 0.7 wt% for samples containing iron powder with average particle size ∼150 μm compacted at 800 MPa. In accordance with this resin content, at high frequencies (>300 kHz), the sample with lower particle size ∼10 μm exhibits higher magnetic permeability, higher operating frequencies and lower imaginary part of permeability. With increase in the compaction pressure, specific resistivity decreases and imaginary and real parts of permeability increase at low frequencies. 相似文献
6.
An InAs ring structure accompanying the formation of quantum dots (QDs) was fabricated on (1 0 0)GaAs using droplet epitaxy. The QDs were located in the vicinity of the ring, due to the diffusion of In atoms from the In droplets. In addition, the dots were found to have distributed elliptically and preferentially along the [0 1 1] direction, implying that In itself prefers to diffuse along the [0 1 1] direction, which is the opposite of the favorable diffusion orientation of group III atoms on (1 0 0)GaAs under a commonly used As-stabilized growth condition. This is the first observation of a ring structure accompanying the formation of quantum dots in droplet epitaxy. 相似文献
7.
Milan S. Trtica Victor F. Tarasenko Andrei V. Fedenev Bojan B. Radak Mikhail A. Shulepov 《Applied Surface Science》2005,252(2):474-482
Interactions of a transversely excited atmospheric (TEA) CO2 laser and an excimer XeCl laser, pulse durations ∼2 μs (initial spike FWHM ∼100 ns) and ∼20 ns (FWHM), respectively, with polycrystalline titanium nitride (TiN) coating deposited on high quality steel AISI 316, were studied. Titanium nitride was surface modified by the laser beams, with an energy density of 20.0 J/cm2 (TEA CO2 laser) and 2.4 J/cm2 (XeCl laser), respectively. The energy absorbed from the CO2 laser beam is partially converted to thermal energy, which generates a series of effects such as melting, vaporization of the molten material, shock waves, etc. The energy from the excimer XeCl laser primarily leads to fast and intense target evaporation. The calculated maximum temperatures on the target surface were 3770 and 6300 K for the TEA CO2 and XeCl lasers, respectively. It is assumed that the TEA CO2 laser affects the target deeper, for a longer time than the XeCl laser. The effects of the XeCl laser are confined to a localized area, near target surface, within a short time period.Morphological modifications of the titanium nitride surface can be summarized as follows: (i) both lasers produced ablation of the TiN coating in the central zone of the irradiated area and creation of grainy structure with near homogeneous distribution; (ii) a hydrodynamic feature, like resolidified droplets of the material, appeared in the surrounding peripheral zone; (iii) the process of irradiation, in both cases, was accompanied by appearance of plasma in front of the target.Target color modifications upon laser irradiation indicate possible chemical changes, possibly oxidation. 相似文献
8.
K. VanchinathanG. Bhagavannarayana K. MuthuS.P. Meenakshisundaram 《Physica B: Condensed Matter》2011,406(22):4195-4199
1,5-Diphenylpenta-1,4-dien-3-one ( dibenzalacetone, DBA) was synthesized by a base-catalyzed aldol condensation reaction between benzaldehyde and acetone. High quality single crystals have been grown by the slow evaporation of ethanol solution and the crystal belongs to monoclinic system with centrosymmetric space group C 2/c. The DBA crystals are transparent in the entire visible region and have a lower optical cutoff at ∼440 nm. It is stable up to 119 °C and has a good chemical stability. The high resolution X-ray diffraction curve (DC) indicates that the specimen is free from structural grain boundaries. Molecular packing leads to a centrosymmetric arrangement resulting in zero second harmonic generation (SHG; χ(2)=0) efficiency. 相似文献
9.
Optical, thermal and dielectric properties of Ni(II)-doped tris(thiourea)zinc(II) sulphate single crystals grown by slow evaporation solution growth technique has been investigated. The lattice parameters of the as-grown crystals were obtained by single crystal X-ray diffraction analysis. The modes of vibrations of different functional groups present were identified by FT-IR studies. The surface morphological changes are observed in the doped specimen. The structure and the crystallinity of the material were confirmed by powder X-ray diffraction analysis. The UV–vis optical absorption spectrum shows the lower optical cut-off at ∼284 nm and the crystals are transparent in the entire visible region. The relative second harmonic generation efficiency measurements reveal the enhancement of efficiency by doping with small quantities of Ni(II). 相似文献
10.
Flavio C. Cruz Jorge D. Marconi Arismar Cerqueira S. Jr. Hugo L. Fragnito 《Optics Communications》2010,283(7):1459-1462
We demonstrate broadband second harmonic generation of low-energy pulses produced by injecting two single-frequency lasers into a highly nonlinear fiber. Full nonlinear conversion of the corresponding spectra, consisting of broadband (∼200 nm) optical frequency combs at ∼1580 nm, were obtained by using conventional birefringence phase-matching in two BIBO crystals (2-mm and 100-μm long) with a normal incidence configuration. The crystals were not tilted and the pulses were not compressed. This broadband conversion results from the large phase-matching bandwidth of the nonlinear BIBO crystals at ∼1550 nm, but also seems to be a consequence of a fundamental comb with small spectral phase variation. 相似文献
11.
Multipod ZnO whiskers were synthesized successfully by two steps: pulsed laser deposition (PLD) and thermal evaporation process. First, a thin layer of Zn films were deposited on Si(1 1 1) substrates by PLD. Then the whiskers grew on Zn-coated Si(1 1 1) substrate by the simple thermal evaporation oxidation of the metallic zinc powder at 900 °C in the air without any catalysts or additives. The pre-deposited Zn films by PLD on the substrate can promote the growth of ZnO multipod whiskers effectively. The as-synthesized ZnO whiskers were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). The results revealed that the whiskers are highly crystalline with the wurtzite hexagonal structure. Room temperature photoluminescence (PL) spectrum of the whiskers shows a UV emission peak at ∼393 nm and a broad green emission peak at ∼517 nm, which was assigned to the near band-edge emission and the deep-level emission, respectively. 相似文献
12.
Single crystals of benzophenone-2-furoyl hydrazone are grown by slow evaporation solution growth technique from ethanol at room temperature. It belongs to monoclinic system with the space group P21/c and the cell parameters are, a = 6.1631(3) Å, b = 13.1397(8) Å, c = 18.0030(11) Å and V = 1457.72(14) Å3. NMR spectral studies reveal the structure and powder XRD indicates the crystallinity of the specimen. The characteristic functional groups present in the molecule are confirmed by Fourier transform infrared spectroscopy. The crystals are transparent in the visible region having a lower optical cut-off at ∼406 nm and the band gap energies are estimated by the application of Kubelka–Munk algorithm. Thermal analysis by TG/DTA indicates the stability of the material. The scanning electron microscopy studies reveal the surface morphology of the as-grown crystal. Theoretical calculations were performed using Hartree–Fock method with 6-31G(d,p) as the basis set for to derive the optimized geometry, dipole moment and first-order molecular hyperpolarizability (β) values. 相似文献
13.
R. Castro-Rodríguez J. Mendez-GamboaI. Perez-Quintana R. Medina-Ezquivel 《Applied Surface Science》2011,257(22):9480-9484
CdS thin films were grown by fast evaporation technique combined with substrate rotation. The source evaporation temperature was maintained at 600 °C and the substrate temperature at 350 °C with background pressure of 1.0 m Torr. The substrates were corning glass 2947 with dimension of 1 in. × 1 in. rotate at 500 rpm during the growth. In order to verify the quality of the CdS films, the samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and optical measurements. The films shown a flat uniformity thickness with growth rate of ∼3.5 nm/s, the orientation was in the cubic-(1 1 1) and hexagonal-(0 0 2) plane in dependence of the growth time, grain size ∼5 nm, roughness uniformity ∼2.7 nm, transmittance in the visible region spectrum ∼80%, energy band gap between 2.39 and 2.42 eV and short circuit photocurrent density (JSC) losses in the CdS films of 4.7 mA/cm2. 相似文献
14.
A new p-type of material for organic field-effect transistors (OFETs) is 5,5′-di(9,9′-di-(butyl)-fluorene′)-2,2′-bithiophene (DBFBT). DBFBT films have been prepared by casting, by thermal evaporation in vacuum, and by means of CO2 laser evaporation. The photon energy from a CO2 laser is too small to break chemical bonds of the DBFBT molecule, but the heating rate is extremely high. Pressed pellets of powders composed of DBFBT and polychlorotrifluoroethylene (PCTFE) were used as targets for the fabrication of films. These targets were irradiated by a laser beam of 40 W cw-power and 0.5 cm diameter. The deposition rate was 30-50 nm/s. The films have been characterised by optical spectroscopy and by AFM. The structure of DBFBT films produced by casting from solution and thermal deposition is composed of elongated crystals, while the laser deposited layers show cluster structure. By FTIR the films show the absorption band of pure DBFBT, with intensity proportional to the DBFBT concentration in the PCTFE matrix. The absorption bands for a pure DBFBT film, for a film with 22 vol.% and with 34 vol.% of DBFBT in the PCTFE matrix are situated at 274, 298 and 402 nm, where the latter is the most intense one. No significant difference in the band positions of all samples has been found. We concluded that no interaction between chromophore and matrix occurs. The DBFBT molecules in the PCTFE matrix did not oxidize during storage under ambient condition over a period of a year. 相似文献
15.
Single crystals of organic material guanidinium phenyl arsonate (GPA) of size 28 × 14 × 10 mm3 were grown from propanol–water mixed solvent by slow solvent evaporation technique. The crystal belongs to monoclinic system with noncentrosymmetric space group Cc. The lattice parameter values of GPA crystals are a = 18.453 Å, b = 7.609 Å, c = 12.592 Å and β = 121.856°. The grown crystal was subjected to X-ray diffraction (XRD) study to identify its morphology and structure. Chemical etching study using propanol–water as etchant reveals the mechanism of growth. The formation of synthesized compound was confirmed by Fourier transform infrared (FT-IR) spectroscopy analysis. Optical transmittance and second harmonic generation (SHG) of the grown crystals were studied by UV–vis–NIR spectrum and Kurtz powder technique respectively. The transmittance of GPA has been used to calculate the refractive index ‘n’ and the extinction coefficient ‘k’. The laser induced surface damage threshold for the grown crystal was determined using Nd:YAG laser. The mechanical behavior of GPA was analyzed using Vickers microhardness test. 相似文献
16.
We study dual-synthetic antiferromagnets (DSyAFs) using Co2FeAl (CFA) Heusler electrodes with a stack structure of Ta/CFA/Ru/CFA/Ru/CFA/Ta. When the thicknesses of the two Ru layers are 0.45 nm, 0.65 nm or 0.45 nm, 1.00 nm, the CFA-based DSyAF has a strong antiferromagnetic coupling between adjacent CFA layers at room temperature with a saturation magnetic field of ∼11,000 Oe, a saturation magnetization of ∼710 emu/cm3 and a coercivity of ∼2.0 Oe. Moreover, the DSyAF has a good thermal stability up to 400 °C, at which CFA films show B2-ordered structure. Therefore, the CFA-based DSyAFs are favorable for applications in future spintronic devices. 相似文献
17.
Single crystal of γ-glycine, an organic nonlinear optical material has been grown by solvent evaporation technique from the aqueous solutions of glycine and cadmium chloride at ambient temperature for the first time. The γ-phase of glycine is confirmed by single crystal X-ray diffraction. The crystal is in hexagonal system with non-centrosymmetric space group P31. The FTIR spectral analysis shows the functional group vibration of γ-phase glycine. UV–vis–NIR analysis reveals that the crystal has good optical transparency window in the entire visible and IR region. UV cut-off wavelength is at ∼350 nm. Thermal analysis shows the thermal stability, phase transition of the grown crystals and its melting point. Second harmonic generation efficiency of the crystal is about 1.7 times that of KDP. 相似文献
18.
Indium-tin oxide (ITO) films deposited on heated and non-heated glass substrates by a pulsed Nd:YAG laser at 355 nm and ∼2.5 J/cm2 were used in the fabrication of simple organic light-emitting diodes (OLEDs), ITO/(PVK + Alq3 + TPD)/Al. The ITO was deposited on heated glass substrates which possessed resistivity as low as ∼3 × 10−4 Ω cm, optical transmission as high as ∼92% and carrier concentration of about ∼5 × 1020 cm−3, were comparable to the commercial ITO. Substrate heating transformed the ITO microstructure from amorphous to polycrystalline, as revealed by the XRD spectrum. While the polycrystalline ITO produced higher OLED brightness, it was still lower than that on the commercial ITO due to surface roughness. A DLC layer of ∼1.5 nm deposited on this ITO at laser fluence of >12.5 J/cm2 improved its device brightness by suppressing the surface roughness effect. 相似文献
19.
Kimin Hong Jungju Lee Jinhan Lee Young-Dong Ko Jin-Seok Chung Jin-Gyu Kim 《Journal of magnetism and magnetic materials》2006
We investigated the change of magnetic properties of the electroplated Cu/Co alloys and multilayers caused by organic additives and high temperature annealing. When plated with a pure Cu/Co electrolyte, the alloy contained ∼25% of Cu and ∼75% of Co. The alloy was made of hcp-Co, fcc-Co and Cu(1 1 1) and was super-paramagnetic at room temperature. As we add a few organic additives in the plating electrolyte, the hcp-Co of the films disappeared. The organic additives contained in the electrolytes changed paramagnetic Cu/Co multilayers to ferromagnets. High-temperature thermal annealing increased coercivity due to the growth of the Co grains. 相似文献
20.
Analysis of polymer electro-optic microring resonator switches 总被引:1,自引:0,他引:1
The structure and the principle for the polymer electro-optic microring resonator (MRR) switch are proposed as well as the transfer functions. The structural parameters are optimized; the transmission characteristics are analyzed including the output power, switching time, switching voltage, insertion loss, and crosstalk. When the operation voltage is 0 V, the insertion loss and crosstalk are ∼1.2 and −20.2 dB, respectively; when the operation voltage is 10.0 V, those are ∼0.35 and −20.0 dB, respectively. Furthermore, a novel method is presented for analyzing time-domain response of the device and the switching time is determined to be ∼10.71 ps. These results indicate the favorable switching functions of the designed device. 相似文献