It is presented in this work a p(a-SiC:H)/i(a-SiC:H)/i((a-Si:H)/ n(a-Si:H) single junction for application in color sensing domain produced with the PECVD technique. The interest of this device resides in its simplicity of realization and utilization, as it takes advantage from the well known properties of the a-Si:H p-i-n junctions together with the possibility of color filtering by tailoring the optical gap of a-Si:H with the introduction of a small percentage of Carbon. The thicknesses of the i(200 nm) and i (1000 nm) layers are optimized for light absorption in the blue and red ranges, respectively. Measurements of the spectral response under forward and reverse polarization show a dependence of the wavelength of the maximum absorption on the intensity of the applied bias. A comparison of the photocurrent reading with and without a 650 nm background DC optical bias permits a complete separation of blue and red color under reverse and forward applied bias, respectively. The application of the LSP technique (AC regime of the optical bias) permits a complete RGB reading of the incoming light.Simulation results obtained with the program ASCA will support and explain the measurements about spectral response and photocurrent reading under DC and AC regimes.

This paper presents the study related to the production of TlBr thin films. Films produced by thermal evaporation present better structural properties than those produced by spray pyrolysis. The main XRD peak of the evaporated films correspond to the (100) plane, whose structure is columnar as revealed by cross section SEM. The thickness decreases with increasing deposition height. Optical band gap of 3.0 eV and electrical resistivities about 109 Ωcm were obtained. EDS reveals a reduction in the amount of Br in the final films. One order of magnitude was obtained for the photo-to-dark current ratio when irradiation in the medical diagnosis X-ray mammography energy range was used.

We report on a high efficiency deep-blue phosphorescent organic light-emitting diode (POLED) based on new electron-transporting host material. The new electron-transporting host material is an adamantane derivative with high triplet energy and high electron mobility. The deep blue POLED that we have developed utilizes a deep-blue phosphorescent guest material, iridium(III)bis(4’,6’,-difluorophenylpyridinato)tetrakis(1-pyrazolyl)borate, and exhibits a power efficiency of about 10.2 lm/W at luminance of 100 cd/m2 and maximum external quantum efficiency (EQE) of about 13 %. The power efficiency of our POLED is much higher than that of POLED using p–bis(triphenylsilyly)benzene (UGH2). The maximum EQE of our POLED was also slightly more than that of POLED using UGH2. The obtained difference in power efficiency originates from the new host material having higher electron mobility than that of UGH2.

An excellent material for thermal neutron detectors is α-rhombohedral boron, due to the large neutron capture cross section of 10B, high hole mobility and ability to self-heal from radiation damage, to date, little work has been done on the crystal growth of α-rhombohedral boron. In this investigation, we attempt to grow α-rhombohedral boron by the solution growth method, employing copper as solvent. Well-faceted transparent red crystals several hundreds of microns in size have been made. Elemental analysis of the crystals detected boron, with negligible amounts of copper, suggesting that copper is a promising solvent for the crystal growth of α-rhombohedral boron crystal.

Gold-coated polystyrene (PS) beads were fabricated by an in situ metallization route involving a cationic-gold complex with a controlled amount of sulfonic acid groups formed on the PS bead surface. The interaction ratio of SO3− to [Au(phen)Cl2]+ may be estimated to be 2.4, which means that 2.4 sulfonated groups will interact with one gold cationic ligand based on geometric considerations. A modeling methodology was developed to predict the mechanical deformation, conductivity, and contact surface area of a spherical bead under compression.

The role of intrinsic point defects on radiative recombination in Cu(In,Ga)Se2 thin films was investigated by photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies. Experiments were performed on device-grade polycrystalline layers and single crystal thin films. PL transitions identified by others as indicating a shallow state with an ionization energy of ∼16 meV is proposed to be a transition into band tail states rather than a distinct shallow defect. The presence of deep levels contributing to radiative recombination does not necessarily preclude the material from producing a high efficiency device and may suggest the absence of dominant non-radiative recombination pathways. The band edge width as measured by PLE and the separation of this edge from defect states are suggested to be potentially effective indicators of the quality of a material. Luminescence that appears to be connected with the absence of Na in the growth process persists in high Ga alloy, Na containing materials, suggesting that Na may become ineffective in passivating or eliminating certain defects in high Ga material.

This paper reports enhanced internal-quantum-efficiency (IQE) in InGaN-based multi-quantum-well (MQW) grown on Si(111) substrate with underlying strained-layer-superlattice (SLS) cladding layer for application in LDs and LEDs. In comparative study between a thick Al0.03Ga0.97N bulk and an Al0.06Ga0.94N/GaN SLS cladding layer, transmission-electron-microscopy (TEM) images reveal that Al0.06Ga0.94N/GaN SLS cladding layer is effective to suppress threading dislocations. A higher IQE has been achieved in sample with underlying Al0.06Ga0.94N/GaN SLS cladding layer, compared to that of Al0.03Ga0.97N bulk cladding layer. IQE of 31.6% has been achieved in sample with underlying Al0.06Ga0.94N/GaN SLS cladding layer when the MQW thickness is reduced to 2 nm.

Pulsed THz wave spectroscopy using air as the THz wave emitter with the excitation of femtosecond laser provides intense (>100 kV/cm) and broadband THz waves (usable bandwidth from 0.3 to 11 THz). Using the air-biased-coherent-detection (ABCD) method, air can also coherently detect pulsed THz waves over a broadband spectrum. By utilizing these two technologies, we developed a prototype THz air photonics time-domain reflection spectrometer, and applied it on many materials in normal reflection geometry. Optical properties of CaCO3 crystals and several other samples in the THz range were studied. The system provided a signal-to-noise ratio (SNR) over 1000:1, with 0.1 cm−1 frequency resolution. The results acquired from both transmission and reflection measurements were then compared.

Conventional growth of zinc oxide (ZnO) nanowires (NWs) is typically carried out using vapor liquid solid (VLS) and chemical vapor deposition (CVD) methods. While these methods are effective, they often involve the use of specialty gasses and equipment. We have discovered that ZnO NWs grow spontaneously from zinc (Zn) films (thermally evaporated on silicon (Si) substrates) when the films are merely heated on a hot-plate in air at ambient pressures for 10 minutes. This process does not involve any metal catalysts, seed layers, specialty gasses or surface treatments in forming patterned regions (on silicon substrates) of NWs with typical diameters in the range of 20-50 nm and lengths of 2-3 μm.

This paper presents the results of atomic force microscope (AFM) measurements of the adhesion force between MDA-MB-231 breast cancer cells and anti-EphA2 antibody-coated AFM tips. As a control, the adhesive interactions are measured between Hs578Bst normal breast cells and anti-EphA2 antibody-coated AFM tips. The measurements show conclusively that the adhesive forces to breast cancer cells are over five times greater than those to normal breast cells. The increase is attributed largely to the interactions between anti-EphA2 antibody and over-expressed EphA2 receptors that are revealed by the staining of receptor-ligand interactions. The implications of the results are discussed for the localized targeting and treatment of cancer with antibody-conjugated nanoparticles.

Additive Manufacturing Technologies (AMTs) have become an appealing method for the fabrication of 3D cellular scaffolds for tissue engineering and regenerative medicine. To circumvent the use of (meth)acrylate based photopolymers, that suffer from skin irritation and sometimes cytotoxicity, new monomers based on vinyl esters, carbonates and carbamates were prepared. The new materials, giving poly(vinyl alcohol) upon hydrolysis, showed similar results compared to (meth)acrylate references concerning the photoreactivity and mechanical properties, yet being significantly less cytotoxic.

To study the kinetics of hydrolytic degradation, the influence of the different polymerizable groups was investigated by hydrolysis of model compounds under alkaline conditions. We were able to show that the ester moiety of a vinyl ester based polymer could be used to immobilize alkaline phosphatase, therefore they exhibit the ability to immobilize enzymes for selective cell adhesion.

Finally, 3D test structures by AMT techniques could be fabricated and in-vivo testing thereof proofed the biocompatibility of vinyl ester-based scaffolds.

In this manuscript, we study the magnetic property of Al-doped/Al2O3-doped ZnO films. We found that metallic Al-doped ZnO film shows room temperature ferromagnetism (RTFM). RTFM is correlated with the interaction of Al metallic clusters and ZnO matrix. The charge transfer has been observed between metallic Al and ZnO matrix. Therefore, RTFM in metallic Al doped ZnO may be highly probable due to charge transfer between metallic Al clusters and ZnO matrix. For Al2O3-doped ZnO film (denoted as (Zn1-x, Alx)O), RTFM was found in (Zn1-x, Alx)O film with a certain Al concentration range (16 mol%<x<50 mol%). The saturation magnetization is maximized in (Zn0.70, Al0.30)O film. The mechanism of RTFM can be explained as the interaction of ZnO nanocrystals (NCs) embedded in the amorphous phase and defects surrounding them.

We employ UV photolithographic and electron beam lithographic patterning of diamond seeding layer on SiO2/Si substrates for the selective growth of micrometer and sub-micrometer diamond patterns. Using bottom-up strategy, thin diamond channels (470 nm in width) are directly grown. Differences between wet chemical and plasma treatment on the patterned diamond growth are studied. We find that the density of parasitic diamond crystals (outside predefined patterns) is lowered for gas mixture CF4/O2 plasma than for rich O2 plasma. After CF4/O2 plasma treatment, the density of parasitic crystals is 106 cm-2 which is comparable to the wet chemical treatment. Introducing sandwich-like structure, i.e. photoresist-seeding layer-photoresist, and its treatment (lift-off and CF4/O2 plasma) further reduces the density of parasitic crystals down to 105 cm-2. The advantage of this novel treatment is short processing time, simplicity, and minimal damage of the substrate surface.

TiO2, TiO2-1at.% W and TiO2-1at.% Cr were produced from metal-organic precursors by flame spray synthesis (FSS). TiO2-0.5at.% N was obtained by ammonolysis of FSS made TiO2 nanopowder in a rotating tube furnace under NH3 atmosphere. According to the X-ray diffraction (XRD) analysis, anatase is the predominant phase in all samples. Diffusive reflectance and the resulting band gap energy (Eg) were determined by diffusive reflection spectroscopy (DRS).Additional impurity bands at 2.43 and 2.57 eV for N- and Cr-doped TiO2, respectively have been observed. The impurity band formed in the band gap resulted in increase of the light absorption in the visible range. The photocatalytic performance of the nanopowders under ultraviolet (UV, 290-410 nm) and visible light irradiation (Vis, 400-500 nm) was studied by the degradation of methylene blue (MB) in aqueous suspensions. It was found that all types of dopants influence the structure, interaction with the visible light as well as photocatalytic activity. Among all nanopowders, TiO2-W exhibited the best photoactivity, much higher than the commercial TiO2-P25 nanopowder. The optimum of the photodecolourization was obtained for 0.7 and 1 at.% W.

In this work we have employed UV-Vis absorbance and excitation techniques in addition to quantum chemical calculations to investigate the probable formation of H-type aggregates of zero charged aryl substituted porphyrin in a guest- host solid state structure. The films were factored via casting technique mixing free-base tetrapyridyl porphyrins (H2TPyP) and polymethilmethacrilate polymer (PMMA) chlorophorm solutions. A pathway for the possible formation of H-type aggregate is suggested.

In this work, ambipolar rubrene single crystal field-effect transistors (FETs) with PMMA modification layer and Au/Ca as electrodes were fabricated. The electron mobility was studied in these devices. PMMA modification layer on the surface of SiO2 is necessary for electron behavior. We found that the device with PMMA modified insulator and Au-Ca asymmetric metals possessed hole mobility and electron mobility of 1.27 and 0.017 cm−2/Vs, respectively. Furthermore, the shift of light emitting with applied gate voltage was observed in this device.

An equivalent circuit for DSCs was studied using electrochemical impedance spectroscopy measurement, and the improvements of conversion efficiency of DSCs for not only single cells but also integrated modules were investigated. Further improvement of cell characteristics of DSCs was also investigated from the view point of modified TiO2 films and series-internal resistance design. The series-internal resistance elements were found to correlate positively with the sheet resistance of the transparent conducting oxide and the thickness of the electrolyte layer and negatively with the roughness factor of the platinum counter-electrode. The short circuit current density (Jsc) of the DSCs was effectively improved by use of a high-haze TiO2 film. In addition, the analysis of TiO2/dye interface by scanning probe microscopy and transient absorption spectroscopy were also useful for the study. As a result, the maximum single cell conversion efficiency of over 11% was obtained. Furthermore, an integrated DSC module composed of many rectangular cells connected in series was fabricated and the efficiency was increased to 8.4% (confirmed by AIST) by realizing high active area and high uniformity.

We present in this communication the preparation and the solid state NMR characterization of phenyl phosphonic acid encapsulated both in pure and aminopropyl-modified SBA-15 mesoporous silica materials. The 31P and 1H MAS studies revealed two radically different behaviors of the confined molecules. The included phosphonic acid in SBA-15 is submitted to a confinement effect that implies a weak interaction with the SiO2 surface and a relative mobility at room temperature. On the contrary, phenyl phosphonic acid molecules in the aminopropyl modified sample possess a strong interaction with the hybrid surface of the material. This finding is supported by a two dimensional double-quantum 1H experiment that revealed the close proximity between phenyl phosphonic acid and aminopropyl surface groups.

Cementum contains specific molecules that could serve to identify, isolate and characterize the cementoblast lineage and to determine the cellular and molecular mechanisms that regulate the cementogenesis process, since it plays a key role during the periodontal regeneration process. One of these molecules is the human cementum protein 1 (CEMP1); which has a molecular weight of 25,9 kDa. In vitro experiments have shown that CEMP1 promotes cellular adhesion and differentiation. In addition, this protein has been implied in regulating the degree of deposition, composition and morphology of hydroxyapatite crystals formed by putative cementoblast in vitro. Therefore, it is possible that CEMP1 promotes the formation, growth and regulates the morphology of hydroxyapatite crystals in vitro. We have produced a human recombinant CEMP1 (hrCEMP1) in a prokaryotic system. The hrCEMP1 purification was realized using the column NiTA HisPrep FF/16. Assays of calcium phosphate crystal growth were realized by means of capillary counterdiffusion system. Our results demonstrated that hrCEMP1 promotes octacalcium phosphate crystal nucleation and possesses high affinity for hydroxyapatite. We infer that hrCEMP1 plays a key role during the regeneration of mineralized tissues.

The effect of the electropulsing on recrystallized microstructure and on texture evolution of a cold rolling (CR) AZ31 strip was studied with the help of light microscopy and X-ray diffraction technique. It was exciting that the completed recrystallization state of sample subjected to the electropulsing treatment (EPT) could be obtained rapidly in ˜7s with the basal texture weakened. The favoring mechanism of static recrystallization (SRX) of MPT could be attributed to the coupled action of the thermal and athermal effects, thereinto, the latter one activated dislocation climb effectively.