共查询到20条相似文献,搜索用时 15 毫秒
1.
M. Stössel J. Staudigel F. Steuber J. Simmerer A. Winnacker 《Applied Physics A: Materials Science & Processing》1999,68(4):387-390
Received: 7 September 1998 / Accepted: 27 November 1998 / Published online: 24 February 1999 相似文献
2.
Fujun Zhang Feng Teng Zhidong Lou Lijian Meng Yongsheng Wang 《Journal of luminescence》2006,117(1):90-94
Silicon dioxide (SiO2) plays an important role in layered optimization scheme and solid-state cathodoluminescence (SSCL). Initially, it was believed that the SiO2 layer would (i) generate extra interface states contributing to a number of primary electrons available for exciting the luminescent centers, and/or (ii) act as acceleration layer resulted in gaining high energy for those electrons that would tunnel into the luminescent layer to excite luminescent centers. Based on the brightness vs. voltage (B-V) measurements, we deem that the latter case, i.e. acceleration and tunneling, is the dominant mechanism. A detailed discussion in terms of electrons acceleration and tunneling as the main contributions to the enhancement of brightness is presented. 相似文献
3.
We report on metal (Cr, Ni, or Pd)-induced solid-phase crystallization (MISPC) of plasma-enhanced chemical-vapor-deposited
hydrogenated amorphous silicon at annealing temperatures ≤600 °C. MISPC is found to significantly reduce the thermal budget
of crystallization at annealing temperatures as low as ∼400 °C. The lowest achievable annealing temperature is found to depend
on the metal type. The metal type is also found to influence grain size and the conductivity of the polycrystalline silicon.
Received: 21 June 1999 / Accepted: 20 October 1999 / Published online: 23 February 2000 相似文献
4.
G. Franzò A. Irrera E.C. Moreira M. Miritello F. Iacona D. Sanfilippo G. Di Stefano P.G. Fallica F. Priolo 《Applied Physics A: Materials Science & Processing》2002,74(1):1-5
We have studied the structural, electrical and optical properties of MOS devices, where the dielectric layer consists of a
substoichiometric SiOx (x<2) thin film deposited by plasma-enhanced chemical vapor deposition. After deposition the samples were annealed at high
temperature (>1000 °C) to induce the separation of the Si and the SiO2 phases with the formation of Si nanocrystals embedded in the insulating matrix. We observed at room temperature a quite intense
electroluminescence (EL) signal with a peak at ∼850 nm. The EL peak position is very similar to that observed in photoluminescence
in the very same device, demonstrating that the observed EL is due to electron–hole recombination in the Si nanocrystals and
not to defects. The effects of the Si concentration in the SiOx layer and of the annealing temperature on the electrical and optical properties of these devices are also reported and discussed.
In particular, it is shown that by increasing the Si content in the SiOx layer the operating voltage of the device decreases and the total efficiency of emission increases. These data are reported
and their implications discussed.
Received: 31 August 2001 / Accepted: 3 September 2001 / Published online: 17 October 2001 相似文献
5.
Khizar-ul-Haq M.A. Khan Z.L. Zhang X.W. Zhang J.M. Wei Jun Li 《Journal of luminescence》2009,129(10):1158-1162
Blue organic light-emitting devices based on wide bandgap host material, 2-(t-butyl)-9, 10-di-(2-naphthyl) anthracene (TBADN), blue fluorescent styrylamine dopant, p-bis(p-N,N-diphenyl-amino-styryl)benzene (DSA-Ph) have been realized by using molybdenum oxide (MoO3) as a buffer layer and 4,7-diphenyl-1,10-phenanthroline (BPhen) as the ETL. The typical device structure used was glass substrate/ITO/MoO3 (5 nm)/NPB (30 nm)/[TBADN: DSA-Ph (3 wt%)](35 nm)/BPhen (12 nm)/LiF (0.8 nm)/Al (100 nm). It was found that the MoO3∥BPhen-based device shows the lowest driving voltage and highest power efficiency among the referenced devices. At the current density of 20 mA/cm2, its driving voltage and power efficiency are 5.4 V and 4.7 Lm/W, respectively, which is independently reduced 46%, and improved 74% compared with those the m-MTDATA∥Alq3 is based on, respectively. The J-V curves of ‘hole-only’ devices reveal that a small hole injection barrier between MoO3∥NPB leads to a strong hole injection, resulting low driving voltage and high power efficiency. The results strongly indicate that carrier injection ability and balance shows a key significance in OLED performance. 相似文献
6.
Increased luminance of MEH-PPV and PFO based PLEDs by using salmon DNA as an electron blocking layer
The effect of salmon DNA-CTMA as an electron blocking layer (EBL) has been examined on the performance of MEH-PPV and PFO-based light emitting diodes. Though the turn-on voltage increases with incorporation of EBL, a significant increase in luminance and luminous efficiency for both the devices is observed. The EBL improves the device performance by blocking electrons at the EBL-polymer interface, thereby increasing the recombination probability of electrons and holes. The luminance of the MEH-PPV based Bio-LED increases to 100 cd/m2 from 30 cd/m2 while a corresponding increase for the PFO based LED is to 160 cd/m2 from 80 cd/m2 with and without EBL, respectively. 相似文献
7.
Tuning of the emission color of organic electroluminescent devices by exciplex formation at the organic solid interface 总被引:1,自引:0,他引:1
′ ,4′′-tris(3-methylphenylphenylamino)triphenylamine, 1,3,5-tris[(4-diphenylaminophenyl)phenylamino]benzene, N, N′-bis(3-methylphenyl)-N, N′-diphenyl-[1,1′-biphenyl]-4,4′-diamine, and 4,4′,4′′-tri(N-carbazolyl)triphenylamine, emitted bright light resulting from the exciplex formed at the solid interface between TPOB
and the hole-transporting material. The exciplex formation was evidenced by the measurements of the photoluminescence spectra
and lifetimes of the mixture of an equimolar amount of TPOB and each of the hole-transporting materials. Tuning of the emission
color from greenish blue to orange was attained by varying the ionization potential of the hole-transporting material for
the fixed electron-transporting material of TPOB.
Received: 27 July 1998/Accepted: 28 July 1998 相似文献
8.
M. Suszynska L. Krajczyk R. Capelletti 《Applied Physics A: Materials Science & Processing》1999,68(4):471-473
2 O-rich droplets dispersed throughout the SiO2-rich matrix and nanoparticles of metallic silver. In exchanged specimens the joint effect of colloidal silver and electric
field results in partial transformation of the amorphous droplets into crystalline Na2O particles.
Received: 11 February 1998 / Accepted: 20 November 1998 / Published online: 24 February 1999 相似文献
9.
J.W. Yoon T. Sasaki N. Koshizaki 《Applied Physics A: Materials Science & Processing》2003,76(4):641-643
Nanocrystalline thin films of complex oxides such as BaTiO3 and LaFeO3 were prepared by pulsed laser ablation without substrate heating. Targets under various Ar pressures were irradiated using
an ArF excimer laser. The off-axis configuration of targets and substrates was used to synthesize the films. The crystallinity
and chemical composition of the deposited films were strongly dependent on the processing Ar gas pressure. In case of BaTiO3, the film deposited at 10 Pa was a single phase of BaTiO3 with a crystallite size around 7.2 nm. With increasing Ar pressure to 200 Pa, XRD peaks of BaTiO3 as well as BaCO3 were observed. The by-products could be due to reaction with carbon dioxide in air after taking the sample out of the chamber.
For LaFeO3, the films deposited under 50 to 200 Pa had a single phase with a crystallite size below 10 nm. When the Ar pressure exceeded
100 Pa, the crystallite size tended to decrease for both BaTiO3 and LaFeO3, which could be due to formation of aggregated nanoparticles. Below 10 Pa, oxygen deficiency was observed. Over 50 Pa, the
atomic concentration of all the constituent elements was almost constant, especially the [Ba]/[Ti] and [La]/[Fe] ratios, which
were nearly unity.
Received: 19 June 2002 / Accepted: 24 June 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +81-298/61-6355, E-mail: yoon-jw@aist.go.jp 相似文献
10.
F.V. Motta A.T. de Figueiredo V.R. Mastelaro L. Gomes E. Longo 《Journal of luminescence》2009,129(7):686-306
The photoluminescence (PL) emission in structurally disordered Ba0.8Ca0.2TiO3 (BCT20) powders was observed at room temperature with laser excitation at lines 355 and 460 nm. The structural evolution perovskite-like titanate BCT20 powders prepared by a soft chemical processing at different annealing temperatures were accompanied by X-ray diffraction (XRD) and X-ray absorption near-edge structure (XANES). Intermediate oxycarbonate phase was identified and your influence with PL emission was discarding. BCT20 annealed at 500 °C displays intense PL emission. The results indicate relationship between broad PL band and order-disorder degree. 相似文献
11.
J. Piqueras B. Méndez R. Plugaru G. Craciun J.A. García A. Remón 《Applied Physics A: Materials Science & Processing》1999,68(3):329-331
Received: 4 May 1998 / Accepted: 30 October 1998 相似文献
12.
The growing curve of light-induced dangling bonds under illumination has been observed for various intensities of illumination in a-Si:H. It is fitted to a stretched exponential function and then two parameters β and τ involved in the function are estimated as a function of saturated dangling bond density . The experimental values of β, τ, and are compared with those calculated based on our model of light-induced defect creation in a-Si:H. 相似文献
13.
The combinatorial fabrication and screening of 2-dimensional (2-d) small molecular UV-violet organic light-emitting device (OLED) arrays, 1-d blue-to-red arrays, 1-d intense white OLED libraries, 1-d arrays to study Förster energy transfer in guest-host OLEDs, and 2-d arrays to study exciplex emission from OLEDs is described. The results demonstrate the power of combinatorial approaches for screening OLED materials and configurations, and for studying their basic properties. 相似文献
14.
V.D. Blank S.G. Buga N.R. Serebryanaya G.A. Dubitsky R.H. Bagramov M.Y. Popov V.M. Prokhorov S.A. Sulyanov 《Applied Physics A: Materials Science & Processing》1997,64(3):247-250
60 in the pressure range and the temperature range were studied. These properties are the specific gravity, specific heat in the range , sound velocities, elastic moduli, electrical properties, resistance to uniaxial stress and stability against oxidation.
These properties are different from those of diamond and other carbon forms. The hardness of ultrahard fullerites exceed the
hardness of diamond. The structures of the samples are described on the basis of X-ray data.
Received: 27 September 1996/Accepted: 19 December 1996 相似文献
15.
J.-Y. Zhang Y.-H. Ye X.-L. Tan X.-M. Bao 《Applied Physics A: Materials Science & Processing》2000,71(3):299-303
Luminescent SiO2 films containing Ge nanocrystals are fabricated by using Ge ion implantation, and metal–oxide–semiconductor structures employing
these films as the active layers show yellow electroluminescence (EL) under both forward and reverse biases. The EL spectra
are strongly dependent on the applied voltage, but slightly on the mean size of Ge nanocrystals. When the forward bias increases
towards 30 V, the EL spectral peak shifts from 590 nm to 485 nm. It is assumed that the EL originates from the recombination
of injected electrons and holes in Ge nanocrystals near the Si/SiO2 interface, or through luminescent centers in the SiO2 matrix near the SiO2/metal interface. The mismatch of the injection amounts between holes and electrons results in the low EL efficiency.
Received: 28 February 2000 / Accepted: 28 March 2000 / Published online: 5 July 2000 相似文献
16.
Organic light-emitting diodes based on the blend of poly (p-phenylene vinylene) (PPV) derivative and naphthyl-imine–gallium
complex have been fabricated by spin-coating method. Blue emission and blue-green variation depending on the ratio of the
PPV derivative to the complex and the applied voltage have been observed. The investigation on PL (photoluminescence) and
EL (electroluminescence) properties demonstrates that the improvement of the luminescent efficiency is related to the injection
balance between holes and electrons, and the color variation is attributed to the variation of the recombination zone.
Received: 7 July 1999 / Accepted: 11 October 1999 / Published online: 8 March 2000 相似文献
17.
The application of the striking electrical and optical properties of amorphous and nano-crystalline silicon in photovoltaic, photonic and nano-electronic devices is attracting increasing attention. In particular, its use both on polymeric substrates and in Integrated Circuit technology for the development of enhanced new devices has shown that processing techniques to produce amorphous hydrogenated and nano-crystalline silicon films avoiding high substrate temperatures are of great importance. A promising strategy to achieve this purpose is the combination of Hot-Wire Chemical Vapor Deposition at 150 °C with Excimer Laser Annealing, thus maintaining the substrate at relatively low temperature during the complete process.In this work we present a numerical analysis of Excimer Laser Annealing, performed at room temperature, of a multilayer structure of thin alternating a-Si:H and nc-Si films deposited on glass and grown by Hot-Wire Chemical Vapor Deposition. A set of two different layer thicknesses a-Si:H (25 nm)/nc-Si (100 nm) and a-Si:H (30 nm)/nc-Si (60 nm) were analysed for a total structure dimension of 900 nm. The aim is to determine the probable temperature profile to achieve controlled localized in depth dehydrogenation.Temperature distribution has been calculated inside the multilayer during the irradiation by a 193 nm Excimer laser, 20 ns pulse length, with energy densities ranging from 50 to 300 mJ/cm2. Calculations allowed us to estimate the dehydrogenation effect in the different layers as well as the structural modifications of the same layers as a function of the applied laser energy.The numerical results have been compared to the experimental ones obtained in similar multilayer structures that have been analysed through Raman spectroscopy and TOF-SIMS in depth profiling mode. 相似文献
18.
W. Wurth 《Applied Physics A: Materials Science & Processing》1997,65(6):597-601
Received: 21 March 1997/Accepted: 12 August 1997 相似文献
19.
Received: 26 November 1996/Accepted: 7 February 1997 相似文献
20.
The silicon carbonitride (SiCN) films were deposited on n-type Si (1 0 0) and glass substrates by the radiofrequency (RF) reactive magnetron sputtering of polycrystalline silicon target under mixed reactive gases of acetylene and nitrogen. The films have been characterized by energy dispersive spectrometer (EDS), atomic force microscope (AFM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and ultraviolet-visible spectrophotometer (UVS). The influence of RF power on the compositional, morphological, structural and optical properties of the SiCN films was investigated. The SiCN films deposited at room temperature are amorphous, and the C, Si and O compositions except N in the films are sensitive to the RF power. The surface roughness and optical band gap decrease as the RF power increases. The main bonds in the SiCN films are C-N, N-Hn, C-Hn, C-C, CN, Si-H and Si-C, and the intensities of the CN, Si-H and C-Hn bonds increase with increment of the RF power. The mechanisms of the influence of RF power on the characteristics of the films are discussed in detail. 相似文献