Conducting polypyrrole (PPy) nanowire array was electrochemically fabricated by using microphase-separated block copolymer (PEOm-b-PMA(Az)n) thin film as an electrode template. Electropolymerization proceeds selectively through the perpendiculary oriented PEO nanocylindrical microdomains on an ITO electrode coated by the above polymer film. The length of the PPy nanowires was controllable in range of 10-120 nm by the thickness of the coated template film and the amount of passed charge. A 10 nm of diameter, 27 nm of periodicity, and 12 of aspect ratio of the crystalline PPy nanowires were successfully achieved. Selective removal of the template is also achieved simply by rinsing with solubility-controlled mixed solvent.

The use of carbon nanotubes (CNT) as interconnects in future integrated circuits (IC) is being considered as a replacement for copper. As this research needs also innovative metrology solutions, we have developed a combined approach for the plane-view analysis of CNT integrated in contact holes where transmission electron microscopy (TEM) enables the quantitative measurement of density and structure of the CNT and where scanning spreading resistance microscopy (SSRM) is used to electrically map the distribution of the CNT. This paper explains the used methodologies in detail and presents results from 300 nm diameter contact holes filled with CNT of 8-12 nm in diameter and a density of about 2 x 1011 cm-2.

Present progress in developments of glassy alloy composites for bit-patterned-media and non-equilibrium Cu-based alloys for conductive materials of electrical connectors are reviewed. It is proven that the imprinting of the Pd-based glassy alloy thin film is favorable for the formation of nano-structured devices. Detailed imprinted morphologies formed by different imprinting conditions were examined. In addition, technology of large area imprinting up to 2.5 inches area has been successfully developed and it is now available for production. These technological developments will be utilized for next generation bit-patterned-media with high data density. A newly developed non-equilibrium Cu-Zr-Ag alloy was prepared into sheet form by the combination of casting, cold rolling and annealing. The alloy sheet exhibited high tensile strength of exceeding 1500 MPa and good electrical conductivity of 30% IACS. However, bending ductility should be improved for the actual production of connector. Through the several examinations, remaining issues that should be solved are discussed in the framework of industrialization and commercialization. These obtained results suggest that the glassy alloy composite or non-equilibrium alloy designed by the glass-forming rules have a great potential to develop innovative products in the near future.

The importance of nanodiamond in biological and technological applications has been recognized, and applied in drug delivery, biochip, sensors and biosensors. Nanodiamond (ND) and nitrogen doped nanodiamond (NND) films were deposited on n-type silicon films, and later functionalized with enzyme glucose oxidase (GOX). Functionalized electrode has been characterized using different techniques; i.e.fourier transform spectroscopy (FTIR) -, Raman spectroscopy, atomic force microscopy (AFM) and electrochemical techniques, respectively. Under this work, the ND/GOX and NND/GOX electrodes have demonstrated providing sensitive glucose concentration response. Besides, the cytotoxic effects of the NDs have been studied in vitro. Human Embryonic Kidney 293 (HEK293) cells are cultured in the presence of the films then toxicity has been detected using MTT-based cytotoxicity assays utilizing 3-(4, 5-Dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT). The final results for MTT assays are quantified by spectrophotometry using a plate reader at 570 nm As-prepared nanodiamond has been found to be stable , biocompatible and useful for biosensing applications. A linear response of the enzyme based electrode to glucose concentration is also observed from 1-8 x mM before saturation condition close to 10mM has been observed.

Plastic deformation in body centered cubic iron is dominated by glide of screw dislocations with non-planar dislocation cores. This causes a strong strain rate and temperature dependence of flow stress, the breakdown of Schmid’s law and a dependence of dislocation mobility on shear stress components that do not contribute to the mechanical driving force for dislocation glide. Based on the framework of crystal plasticity, we developed a constitutive plasticity model that takes all these phenomena into account. To parameterize this continuum plasticity model molecular statics simulations using a semi-empirical potential have been performed. These atomistic calculations yielded quantitative relationships for the influence of all components of the local stress tensor on dislocation mobility. Together with experimental data from the literature on the kinetics of screw dislocations in bcc iron the constitutive relation presented here has been developed. As application example of the model, we calculated the tension compression asymmetry and the strain rate dependence of the hardening behavior within a bcc iron crystal.

The aim of this study is to analyze and mitigate the voltage drift phenomenon observed in top-emitting organic light emitting diodes (OLED) when driven at constant current. An operating device may experience voltage increase over time due to factors such as interface or bulk material degradation, charge accumulation and formation of trap states. Single-carrier devices were fabricated to understand the contribution to voltage drift from each of these causes. Doping in electron injection layer (4, 7-diphenyl-1,10-phenanthroline or Bphen) and hole injection layer (2,2’,7,7’-tetra(N,N-di-tolyl)amino-spiro-bifluorene or Spiro-TTB) were optimized to obtain ohmic injection contacts. Devices with tris(8-hydroxy-quinoline) aluminium (Alq3) degrade significantly with holes injection and undergo high voltage increase in lifetime test measurements. On the contrary, devices with N,N’-di(naphtalen-1-y1)-N,N’-diphenyl-benzidine (NPB) exhibit an ambipolar charge transport behavior and low voltage drift under both hole and electron injection.

In this work, room temperature co-deposition of Mg and Si was used to successfully fabricate Mg2Si thin films on Si substrate by dual cathode magnetron sputtering (DCMS). Films were annealed at 380°C. Various Mg/Si sputtering power ratios have been examined. XRD, SEM and IR reflectivity measurements on grown and annealed films, reveal that annealing is enhancing the formation of crystalline Mg2Si.

On the basis of ab initio molecular dynamics modeling, we show that Ge-Sb-Te alloy under excitation can realize amorphization without going through a liquid phase. The electronic structure analysis further reveals that the excitation mainly involves the Ge s-like states near the valence band maximum. After the phase transition, the coordination number of Ge is reduced from six to four, while the change in the coordination number for Sb is noticeably less.

New ventures in the nanomaterials industry are subject to the same laws of physics as all other entities – they compete for capital, customers, and work through similar variables. Ultimately, success is determined by the degree to which customers prefer the new venture product(s) to alternatives, thus, thinking from the perspective of the customer is critical to success. Often we focus on what the idea is, how it improves on alternatives in the marketplace, and don’t spend adequate time considering the world from the customer’s view. In reviewing choices that must be made and examples of successes and failures, the case for a thorough business plan is presented.

Growth process of microcrystalline silicon (μc-Si:H) using plasma-enhanced chemicalvapor- deposition method under high-rate-growth condition has been studied for the control of optoelectronic properties in the resulting materials. We have found two important things for the spatial-defect distribution in the resulting μc-Si:H through a precise dangling-bond-density measurement, e. g., (1) dangling-bond defects are uniformly distributed in the bulk region of μc- Si:H films independent of their crystallite size and (2) large number of dangling bonds are located at the surface of μc-Si:H especially when the film is deposited at high growth rate. Starting procedure of film growth has been investigated as an important process to control the dangling-bond-defect density in the bulk region of resulting μc-Si:H through the change in the electron temperature by the presence of particulates produced at the starting period of the plasma. Deposition of Si-compress thin layer on μc-Si:H grown at high rate followed by thermal annealing has been proposed as an effective method to reduce the defect density at the surface of resulting μc-Si:H. Utilizing the starting-procedure-controlling method and the compress-layerdeposition method together with several interface-controlling methods, we have demonstrated the fabrication of high conversion-efficiency (9.27%) substrate-type (n-i-p) μc-Si:H solar cells whose intrinsic μc-Si:H layer is deposited at high growth rate of 2.3 nm/sec.

Polymerized C60 crystals were grown using the free electron laser (FEL) irradiation. In order to promote the polymerization degree, hole or electron was doped in the C60 crystals grown by the liquid-liquid interfacial precipitation (LLIP) method to eliminate the degradation by oxidation. The specimen grown with the I2 dissolved butylalcohol (BTA, CH3(CH2)3OH) and the C60 saturation o-xylene solution, subsequently pressed at 7GPa, showed only Ag(2)-derived mode at 1456 cm-1 after the FEL irradiation. The specimen belonged to so-called F phase, which is not obtained by the typical photo-induced polymerization process. It was noted that the FEL irradiation for polymerization of C60 was quite useful.

The use of Voltage Waveform Tailoring (VWT) – that is the use of non-sinusoidal waveforms with a period equivalent to RF frequencies – is shown to be effective in modifying the electric field distribution in a parallel plate, capacitively coupled laboratory plasma deposition reactor, and thus in changing the growth mode of silicon thin films from amorphous to nanocrystalline. The use of the VWT technique allows one to decouple the power injected into the plasma from the ion-bombardment energy at the film surface without changing any other deposition parameters, such as pressure or gas mixture. Material results are presented for an H2/SiH4 gas composition. A “peaks” type waveform increases the ion-bombardment energy at the RF electrode and reduces it at the substrate, resulting in more nanocrystalline growth. The use of a “valleys”-type waveform has the opposite effect, and results in more amorphous growth. We show the dependence of the process on silane dilution and pressure, including results on changes to the deposition rate when changing the excitation voltage waveform.

Hydrogenation of polycrystalline silicon thin-film solar cells is performed to improve the one-sun open-circuit voltage (Voc ) of the device. Voc is found to increase linearly with increasing hydrogenation temperature and then saturates. For planar and textured samples, the Voc saturates at about 340 ºC and 307 ºC respectively. The low hydrogenation temperature helps to lower thermal budget during industrial process. Arrhenius plot of Voc prior to the saturation shows that the textured samples have lower activation energies than the planar sample. The activation energies of samples 188 (planar), 788 (textured) and 888 (textured) are 1.31 eV, 0.86 eV and 0.92 eV, respectively. The lower activation energies of the textured samples could be due to the shorter diffusion thickness and the increased surface area that is exposed to the hydrogen plasma.

We investigated the electrical properties and transmission line performance of indium antimonide nanowires. The results indicate that the of nanowires suffer from low mobility values on the order of 10-to-15 cm2V-1s-1 because of the contact resistances, scattering due to their small diameters, crystal defects and oxidation occurs during growth and cooling. nanowires show extremely inductive behavior during the AC measurements and due to these parasitic parameters, they can sustain transmission for the signals having frequencies up to 10 MHz. The bandwidth of the nanowires is directly proportional to the diameter of the nanowires. Improving the mobility to higher values and introducing de-embedding and impedance matching to the measurements and analysis could easily carry the bandwidth beyond GHz levels.

In this work, we report the synthesis and characterization of three dimensional heterostructures graphene nanostructures (HGN) comprising continuous large area graphene layers and ZnO nanostructures, fabricated via chemical vapor deposition. Characterization of large area HGN demonstrates that it consists of 1-5 layers of graphene, and exhibits high optical transmittance and enhanced electrical conductivity. Electron microscopy investigation of the three dimensional heterostructures shows that the morphology of ZnO nanostructures is highly dependent on the growth temperature. It is observed that ordered crystalline ZnO nanostructures are preferably grown along the <0001> direction. Ultraviolet spectroscopy indicates that the CVD grown HGN layers has excellent optical properties. A combination of electrical and optical properties of graphene and ZnO building blocks in ZnO based HGN provides unique characteristics for opportunities in future optoelectronic devices.

Developments in non-invasive analytical techniques advance the preservation of cultural heritage materials by identifying and analyzing substrates and media. Spectral imaging systems have been used as a tool for non-invasive characterization of cultural heritage, allowing the collection of chemical identification information about materials without sampling. The Library of Congress has been developing the application of hyperspectral imaging to the preservation and analysis of cultural heritage materials as a powerful, non-contact technique to allow non-invasive characterization of materials, by identifying and characterizing colorants, inks and substrates through their unique spectral response, monitoring deterioration or changes due to exhibit and other environmental conditions, and capturing lost and deteriorated information. The resulting image cube creates a new “digital cultural object” that is related to, but recognized as a distinct entity from the original. The range of data this object contains encourages multidisciplinary collaboration for the integration of preservation, societal and cultural information.

Silicon is by far the most successful material in the microelectronics industry enjoying a well-established fabrication and processing infrastructure. Two of the main challenges in traditional silicon electronic devices are (a) silicon’s relatively small and indirect fundamental energy band-gap, which severely limits optoelectronic applications, and (b) the absence of a suitable material to form a heterojunction barrier on silicon. Silicon based nanostructures are being explored as potential candidates to extent the applications of silicon in optoelectronics, provide for high-speed silicon quantum devices, increase the efficiency and reduce the cost in silicon photovoltaic solar cells, and facilitate cost-effective silicon sensors for biological, environmental, and other applications. Quantum size silicon nanolayers, nanowires, and nanodots embedded in oxide, nitride, and other amorphous matrices may provide an effective barrier for silicon, as well as band-gap engineering and enhanced optical transitions for solar cell and optoelectronic applications.

Solution-based printing and coating processes have the potential todramatically reduce the production costs of Organic Light Emitting Diodes.This is particularly true for Quantum Dots Light Emitting Diode (QDLEDs),the newborn in the field of LEDs, due to quantum dots price prohibitingwastage. Here, we report our latest results on the development ofsolutionprocessed QDLEDs. We have implemented a layer by layer strategy,from a whole evaporated small molecule based OLED to a hybrid QDLEDdeveloped by wet deposition techniques for the first layers and byevaporation for the last ones. Intermediate steps are discussed in thispaper.

First, we have worked on a poly(3,4-ethylenedioxythiophenepoly(styrenesulfonate) (PEDOT:PSS) layer. The PEDOT:PSS formulation forinkjet printing and spin coating were optimised: wettability on an ITOsubstrate, jettability of the inkjet formulation and baking conditions werestudied. Additives as surfactant and ethylene glycol were added to thecommercial inkjet grade solution to improve the deposition process. As aconsequence to this study, anisotropic conductivity of PEDOT:PSS wasobserved and is reported here. In particular, ethylene glycol demonstrated astrong ability to increase the parallel conductivity by several orders ofmagnitude, but not the vertical one.

Then, inkjet-printed and spin-coated device performances are compared tocomplete this first study. Hybrid devices with an efficacy of 12cd/A at 4Vwere obtained, with 2.17 % of EQE, and a luminance of 4000 cd/m2at 4V.

Finally, we succeeded in the development of our first QDLED based on CdSecore/ CdSZnS shell quantum dots emitting at a wavelength of 600nm. Quantumdots were inkjet printed, in order to waste as little as possible this veryexpensive material.

Structural and magneto-optical properties of Ni-doped amorphous AlN layers (a-AlN) deposited by radio frequency (rf) sputtering on Silicon (001) substrates were investigated. The as-grown material exhibits weak ferromagnetic behavior as evidenced by the magneto-optic Kerr effect (MOKE) measurement with Kerr rotation less than 100 μrad at room temperature regardless of the Ni fraction. The samples with a Ni concentration below 10 at.% show a weak but monotonically increasing MOKE signal with post-growth annealing temperature. A hundred-fold increase in the Kerr rotation value was observed for samples with Ni content exceeding 20 at.% after thermal annealing at 450°C in nitrogen; and the Kerr rotation value abruptly decreases above that temperature. The morphology of as-grown and annealed a-AlN:Ni films were characterized by small angle x-ray scattering and transmission electron microscopy. It was found that the as-deposited film contains nano-particles of different sizes with average diameters less than 30 nm. The size distribution of nano-particles in the thermally annealed a-AlN:Ni was studied as a function of annealing time and temperature. The results correlate well with those obtained from the MOKE measurements.

Ion implantation of Ge2Sb2Te5 (GST) enables localized doping of the film by using conventional lithography. Although the doped region dimensions and the doping concentration profile are defined by the opening in the mask and the ion energy, longitudinal and lateral straggling of implanted ions leads to a spread in the ions final location. Additionally, a thermal treatment such as one that induces a phase transition may lead to redistribution of the implanted dopants and further increase the spread. In this work we demonstrate doping of GST by ion implantation. Using Secondary Ion Mass Spectrometry (SIMS) we studied the as-implanted doping profiles obtain by ion implantation of carbon and silicon into GST. We also investigated by SIMS the dopant redistribution following a recrystallization annealing. The as-implanted ion profiles were found to be in fair agreement with TRIM simulation. The dopants profiles show little change after a crystallization annealing at 200°C for silicon doping and at 350°C for carbon doping.