排序方式: 共有12条查询结果,搜索用时 15 毫秒
1.
Akram Shahrjerdi Saied Saeed Hosseiny Davarani Mostafa Mohammadpour Amini Ezzatollah Najafi Mohammad Janghouri Ezeddine Mohajerani Aziz Dehpour 《Journal of Materials Science》2014,49(1):441-449
A new lead complex, [Pb(mq)2], (mq = 2-methyl-8-hydroxyquinoline) was prepared via an electrochemical route from the oxidation of lead metal in the presence of 2-methyl-8-hydroxyquinoline in a fast and facile process. The complex was fully characterized by means of NMR and IR spectra and elemental analysis. The nanostructure of the prepared compound was obtained by sonoelectrochemical process and studied by scanning electron microscopy, atomic force microscopy, X-ray powder diffraction, IR spectroscopy and elemental analysis. Thermal stability of single crystalline and nanosize samples of the prepared compound was studied by thermal gravimetric and differential thermal analysis. The photoluminescence properties of the prepared compounds, as single crystals and as nanorods, have been investigated. The results showed a good correlation between the size and the shape of the complex particles and emission wavelength. The prepared complex was doped in PVK:PBD blend as guest and its application in the fabrication of OLED was studied. The ratio of lead complex was modified and was equal to 8 (w/w %) in PVK:PBD (100:40). 相似文献
2.
A. Shahrjerdi F. Mustapha M. Bayat D. L. A. Majid 《Journal of Mechanical Science and Technology》2011,25(9):2195-2209
Second-order shear deformation theory (SSDT) is employed to analyze vibration of temperature-dependent solar functionally
graded plates (SFGP’s). Power law material properties and linear steady-state thermal loads are assumed to be graded along
the thickness. Two different types of SFGP’s such as ZrO2/Ti-6Al-4V and Si3N4/SUS304 are considered. Uniform, linear, nonlinear, heat-flux and sinusoidal thermal conditions are imposed at the upper and
lower surface for simply supported SFGPs. The energy method is applied to derive equilibrium equations, and solution is based
on Fourier series that satisfy the boundary conditions (Navier’s method). Non-dimensional results are compared for temperature-dependent
and temperature-independent SFGP’s and validated with known results in the literature. Numerical results indicate the effect
of material composition, plate geometry, and temperature fields on the vibration characteristics and mode shapes. The results
obtained using the SSDT are very close to results from other shear deformation theories. 相似文献
3.
Fabrication of nickel nanocrystal flash memories using a polymeric approach is presented. Heat treatment of the poly (styrene-b-methyl methacrylate) block copolymer with a molecular weight of 67 000 g/mol followed by PMMA removal in an organic solvent created a porous PS film with 20-nm-diameter pores and a total pore density of ~6 times 1010 cm-2. A trilayer pattern-transfer approach was employed in order to solve the metal lift-off issue intertwined with the low aspect ratio block copolymer patterns. As a result, a highly uniform self- assembled array of nickel nanocrystals was attained and utilized for flash memory fabrication. The memory devices demonstrated an unchanged memory window for up to 2 times 105 stressing cycles. 相似文献
4.
F. Ferdousi J. Sarkar S. Tang D. Shahrjerdi T. Akyol E. Tutuc S.K. Banerjee 《Journal of Electronic Materials》2009,38(3):438-442
This work presents vertical flash memory devices with protein-assembled PbSe nanocrystals as a floating gate and Al2O3 as a control oxide. The advantage of a vertical structure is that it improves cell density. Protein assembly improves uniformity
of nanocrystals, which reduces threshold voltage variation among devices. The introduction of Al2O3 as a control oxide provided lower voltage/faster operation and hence less power consumption compared with the devices fabricated
with SiO2. The integration of Al2O3 appeared to be compatible with the protein assembly approach. In conclusion, Al2O3 has the potential to become the high-k control oxide due to its relatively high electron/hole barrier heights, and high permittivity. 相似文献
5.
D. Shahrjerdi B. Hekmatshoar S. S. Mohajerzadeh A. Khakifirooz M. Robertson 《Journal of Electronic Materials》2004,33(4):353-357
Depletion-mode poly-Ge thin-film transistors (TFTs) with an effective hole mobility of 110 cm2/Vs and an ON/OFF ratio of 104 have been fabricated on flexible polyethylene therephtalate (PET) substrates, taking advantage of a novel stress-assisted
crystallization technique. Proper manipulation of an otherwise destructive mechanical stress leads to a drastic drop of crystallization
temperature from 400°C to 130°C. External compressive stress is transferred to the Ge/PET interface by bending the flexible
substrate inward, during the thermal post-treatment. Proper patterning of the a-Ge layer before thermomechanical post-treatment
leads to a minimal crack density in the processed poly-Ge layer. Reduction in the crack density plays a crucial role in alleviating
the stress-induced gate leakage current emanated from the crack traces propagating from the channel into the gate oxide. 相似文献
6.
7.
Nah J. Liu E-S. Varahramyan K. M. Shahrjerdi D. Banerjee S. K. Tutuc E. 《Electron Devices, IEEE Transactions on》2010,57(2):491-495
8.
Ting Wu Abdullah Alharbi Roozbeh Kiani Davood Shahrjerdi 《Advanced materials (Deerfield Beach, Fla.)》2019,31(6)
A major difficulty in implementing carbon‐based electrode arrays with high device‐packing density is to ensure homogeneous and high sensitivities across the array. Overcoming this obstacle requires quantitative microscopic models that can accurately predict electrode sensitivity from its material structure. Such models are currently lacking. Here, it is shown that the sensitivity of graphene electrodes to dopamine and serotonin neurochemicals in fast‐scan cyclic voltammetry measurements is strongly linked to point defects, whereas it is unaffected by line defects. Using the physics of point defects in graphene, a microscopic model is introduced that explains how point defects determine sensitivity. The predictions of this model match the empirical observation that sensitivity linearly increases with the density of point defects. This model is used to guide the nanoengineering of graphene structures for optimum sensitivity. This approach achieves reproducible fabrication of miniaturized sensors with extraordinarily higher sensitivity than conventional materials. These results lay the foundation for new integrated electrochemical sensor arrays based on nanoengineered graphene. 相似文献
9.
Bahman Hekmatshoar Arash Khajooeizadeh Shams Mohajerzadeh Davood Shahrjerdi Ebrahim Asl-Soleimani 《Materials Science in Semiconductor Processing》2004,7(4-6):419
Device-quality poly-Ge layers were grown at temperatures as low as 200 °C by successive hydrogenation and annealing steps, with no need to any metal incorporation. Hydrogenation is performed in a PECVD apparatus with 150 W RF hydrogen plasma and annealing is carried out in the same system in N2 ambient. As a result, grains of the order of 100 nm are formed in the Ge layer. It has been observed that hydrogenation at high temperatures may be destructive to the Ge layer. Successive hydrogenation and annealing at respective temperatures of 150 and 200 °C would result in a device-quality poly crystalline Ge layer which has been employed for fabrication of depletion-mode thin-film transistors. These TFTs show a field-effect mobility of 80 cm2/Vs for holes and an ON/OFF ratio of more than 103, indicating the feasibility of this technique for applications in large-area electronics. 相似文献
10.
D. Shahrjerdi B. Hekmatshoar S. W. Bedell M. Hopstaken D. K. Sadana 《Journal of Electronic Materials》2012,41(3):494-497
We report epitaxial growth of compressively strained silicon directly on (100) silicon substrates by plasma-enhanced chemical
vapor deposition. The silicon epitaxy was performed in a silane and hydrogen gas mixture at temperatures as low as 150°C.
We investigate the effect of hydrogen dilution during the silicon epitaxy on the strain level by high-resolution x-ray diffraction.
Additionally, triple-axis x-ray reciprocal-space mapping of the samples indicates that (i) the epitaxial layers are fully
strained and (ii) the strain is graded. Secondary-ion mass spectrometry depth profiling reveals the correlation between the
strain gradient and the hydrogen concentration profile within the epitaxial layers. Furthermore, heavily phosphorus-doped
layers with an electrically active doping concentration of ~2 × 1020 cm−3 were obtained at such low growth temperatures. 相似文献