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All silicon-rich silicon carbide (Si-rich SixC1−x)-based single p–i–n junction photovoltaic solar cells (PVSCs) were fabricated by growing nonstoichiometric Si-rich SixC1−x films through medium-temperature hydrogen-free plasma enhanced chemical vapor deposition. The Si-rich SixC1−x-based thin-film p–i–n junction PVSCs exhibit improved power conversion efficiency when an intrinsic Si-rich SixC1−x absorbing layer with a low C/Si composition ratio is added; amorphous Si (a-Si) particles are embedded in this absorbing layer. Lowering the [CH4]/[CH4 + SiH4] fluence ratio from 0.5 to 0.3 reduces the C/Si composition ratio of Si-rich SixC1−x films from 0.74 to 0.665. The absorbance of these films in the visible light region (400–800 nm) is substantially enhanced to 3.8 × 105 cm−1 by reducing the [CH4]/[CH4 + SiH4] fluence ratio, which is up to one order of magnitude larger than that of crystalline Si. The open-circuit voltage and short-circuit current density of the indium tin oxide/p-SixC1−x/i-SixC1−x/nSixC1−x/Al PVSCs are enhanced to 0.51 V and to 19.7 mA cm−2, respectively, raising the conversion efficiency and filling factor to 2.24% and 0.264, respectively. Through hydrogen-free deposition of the Si-rich SixC1−x p–i–n cells on a-Si based p–i–n cells, Si-rich SixC1−x/a-Si hybrid tandem PVSCs exhibit enhanced conversion efficiency and an enhanced filling factor of 6.47% and 0.332, respectively.

The epitaxy of high-power gallium nitride (GaN) light-emitting diode (LED) on amorphous silicon carbide (a-SixC1−x) buffer is demonstrated. The a-SixC1−x buffers with different nonstoichiometric C/Si composition ratios are synthesized on SiO2/Si substrate by using a low-temperature plasma enhanced chemical vapor deposition. The GaN LEDs on different SixC1−x buffers exhibit different EL and C-V characteristics because of the extended strain induced interfacial defects. The EL power decays when increasing the Si content of SixC1−x buffer. The C-rich SixC1−x favors the GaN epitaxy and enables the strain relaxation to suppress the probability of Auger recombination. When the SixC1−x buffer changes from Si-rich to C-rich condition, the EL peak wavelengh shifts from 446 nm to 450 nm. Moreover, the uniform distribution contour of EL intensity spreads between the anode and the cathode because the traping density of the interfacial defect gradually reduces. In comparison with the GaN LED grown on Si-rich SixC1−x buffer, the device deposited on C-rich SixC1−x buffer shows a lower turn-on voltage, a higher output power, an external quantum efficiency and an efficiency droop of 2.48 V, 106 mW, 42.3% and 7%, respectively.

The improvement of current injection efficiency in organic light emitting diodes is demonstrated with incorporation of SubPc-doped NPB as hole injection layers. The photoemission spectra illustrate the presence of gap states and the occurrence of axial reaction on SubPc with NPB. Quantum chemistry calculation provides simulated valence-band spectra indicating that the formation of gap states is due to the HOMOs of new complexes created from the reaction of SubPc and NPB, which facilitate the hole injection at the anode interfaces.

This work focuses on studying the effect of flow velocity on microcantilever-based biosensor by numerical simulation. The microcantilever sensors used in detecting biomolecules have attractive advantages like cost efficiency, real-time and ability of fabricating in array. Both rectangular and triangular shapes of a general model of microcantilever beam are considered. Several important physical phenomena are obtained. Comparing with the first order Langmuir theory, we have calculated the effect on the reactive rate, produced concentration, the distribution of concentration and deflection in the z axis by solving these physical coupled problem involving flow field, concentration field and chemical reaction on the reaction surface. It is found numerically that the transportation of analyte, reactive rate, the distribution of concentration and deflection in the z axis are all effected by changing the flow velocity. The result has shown that flow velocity is an important factor for this biosensor.

Graphene thin films have great potential to function as transparent electrodes in organic electronic devices, due to their excellent conductivity and high transparency. Recently, organic light-emitting diodes (OLEDs)have been successfully demonstrated to possess high luminous efficiencies with p-doped graphene anodes. However, reliable methods to fabricate n-doped graphene cathodes have been lacking, which would limit the application of graphene in flexible electronics. In this paper, we demonstrate fully solution-processed OLEDs with n-type doped multilayer graphene as the top electrode. The work function and sheet resistance of graphene are modified by an aqueous process which can also transfer graphene on organic devices as the top electrodes. With n-doped graphene layers used as the top cathode, all-solution processed transparent OLEDs can be fabricated without any vacuum process.

We demonstrate an alternating current (AC)-driven organic light emitting diodes (OLED) with lithium fluoride (LiF) insulating layers fabricated using simple thermal evaporation. Thermal evaporated LiF provides high stability and excellent capacitance for insulating layers in AC devices. The device requires a relatively low turn-on voltage of 7.1 V with maximum luminance of 87 cd/m(2) obtained at 10 kHz and 15 Vrms. Ultraviolet photoemission spectroscopy and inverse photoemission spectroscopy are employed simultaneously to examine the electronic band structure of the materials in AC-driven OLED and to elucidate the operating mechanism, optical properties and electrical characteristics. The time-resolved luminance is also used to verify the device performance when driven by AC voltage.

OBJECTIVE Thyroid stimulating hormone receptor antibodies (TSHRAbs) are specific autoantibodies of Graves' disease (GD). They activate adenylate cyclase, induce thyroid growth, and cause an increased rate of thyroid hormone production and secretion. TSHRAbs levels are decreased by treatment and may predict recurrence when they persist. Theoretically, TSHRAbs levels should be related to intrathyroid vascularity (ITV) due to the autoimmunity and inflammation. We aimed to analyze the relationship between TSHRAbs represented by thyrotropin-binding inhibitory immunoglobulin (TBII) levels and ITV measured by thyroid duplex sonography (TDS). PATIENTS 56 GD patients were prospectively recruited. MEASUREMENTS ITV, measured using TDS, was defined as follows: (average color-flow area in the right and left sides of the thyroid/total thyroid area in transverse view)×100. RESULTS The average TBII level was 47.1% and average ITV was 27.24. ITV positively and significantly correlated with TBII (p

A semi-transparent silicon-rich (Si-rich) silicon carbide (SixC1−x) based thin-film p–i–n junction photovoltaic solar cell is demonstrated, which is synthesized by hydrogen-free plasma enhanced chemical vapor deposition (PECVD) with the conversion efficiency optimized by detuning plasma power and intrinsic layer thickness. The hydrogen-free PECVD process effectively decelerates the decomposition of hydrogen from the Si-rich SixC1−x films so as to facilitate the passivation of surface dangling bonds. When synthesizing at a fluence ratio of R = [CH4]/[SiH4]+[CH4] = 60%, the optical bandgap of Si-rich SixC1−x film is greatly red-shifted to 1.54 eV due to the enhancement of Si content. By reducing the RF plasma power to 20 W, the Si-rich SixC1−x enlarges its above-bandgap (λ= 0.4–0.8 μm) optical absorption up to 104–105 cm−1, which is even one order of magnitude larger than that of bulk crystalline Si. The incomplete dissociation of CH4 and SiH4 under low-power PECVD growth also helps to suppress the defects and improve the electrical properties of Si-rich SixC1−x. By doping with the PH3 and B2H6 fluence ratios of 5.8% and 2.1%, the resistivities of n-type and p-type Si-rich SixC1−x films are decreased to 0.87 and 0.12 Ω cm, respectively. Thinning the intrinsic Si-rich SixC1−x layer to 25 nm further promotes the conversion efficiency of the Si-rich SixC1−x based p–i–n photovoltaic solar cell. After annealing at 650 °C, the open-circuit voltage (Voc) and short-circuit photocurrent density (Jsc) of the annealed Si-rich SixC1−x and amorphous Si based dual-junction thin-film photovoltaic solar cell are increased to 0.78 V and 19.1 mA cm−2, respectively, leading to a filling factor of 35% and a conversion efficiency of up to 5.24%.

Without the need of single-layer graphene, the graphite nano-sheet powder electrochemically exfoliated from graphite foil can also be employed as a stable saturable absorber and mode-locker for fiber lasers. High-quality graphite nano-sheets containing few graphene layers can be obtained by slow electrochemical exfoliation without the need of post annealing procedure. With reducing the electrochemical exfoliation bias of the graphite foil based anode from + 6 and + 3 volts, the electrochemically exfoliated graphite nano-sheets reveals a decreased D-band intensity in Raman scattering spectrum, and the 2D-band intensity is concurrently enlarged by two times to support the improved quality with suppressed oxidation during the exfoliation reaction. The X-ray photoelectron spectroscopy also confirms the suppression of the C-O bonds in the graphite nano-sheets obtained with decreasing the exfoliation bias. After centrifugation, the average diameter of the exfoliated graphite nano-sheets extracted from the acetone solution is shrunk from 7 μm to 100 nm as the anode bias decreases from 6 to 3 volts. Both the quality and size distribution of the graphite nano-sheets are improved with such slow but refined electrochemical exfoliation. In application, the graphite nano-sheets obtained at different exfoliation bias show relatively stable saturable absorption and passive mode-locking performance in Erbium doped fiber lasers (EDFLs). Benefiting from the advantages of high-gain and strong pulse compression in the EDFL, the graphite nano-sheets with different modulation depths only behave as a mode-locking starter and show trivial influence to the pulse shortening in the mode-locked EDFL, indicating that the strong soliton compression mechanism dominates the generation of 430-450 fs pulsewidth in the EDFL passively mode-locked by graphite nano-sheets.

The surface tensions of the mixed systems consisting of sodium di-2-ethylhexyl sulfosuccinate (Aerosol OT) and homogeneous polyoxyethylene glycol-n-dodecyl ether (nED; n=5 to 8) were measured in the absence and presence of sodium chloride (NaCl) by a modified Wilhelmy plate method.

When a nonionic surfactant, such as hexaoxyethylene glycol dodecyl ethers (6ED) is added to an aqueous iodine solution in the presence of potassium iodide, some spectral changes corresponding to the interaction of iodine-potassium iodide mixture with 6ED are found above the critical micelle concentration (CMC) of 6ED. The absorption maximum bands of complexes formed between 6ED and iodine are significantly different from those formed between 6ED and iodine-potassium iodide mixture in aqueous solution. The complexes of iodic compounds (such as iodine, triiodide ion and polyiodide ion) with 6ED show absorption bands at 390 nm, 370 nm and 385 nm which are assigned to an interaction between iodine-6ED, triiodide ion-6ED and polyiodide ion-6ED, respectively. When the concentration of polyethylene glycol (PEG, MW=200–600) becomes high in aqueous triiodide ion solution, the maximum absorption wavelength of triiodide ion solution also shifts toward 370 nm, similar to that of the triiodide ion-6ED complex. If it is assumed that the absorbance between I3 − and the EO chain in 6ED is the same as that between I3 − and the EO chain of PEG, the concept of effective EO number can be applied to explain the behavior in the absorption spectra among I3 −, 6ED and PEG. Here, the effective EO number is defined as the product of EO chain length and concentration of each 6ED and PEG in the complexes. The effective EO number and concentration of PEG decrease in the triiodide ion-PEG complex as the molecular weight of PEG becomes large. Moreover, the effective EO number and concentration of 6ED are lower than those of PEG at all maximum absorption wavelengths.

Interactions of a nonionic surfactant such as hexaoxyethylene glycol dodecyl ether (6 ED) with several anionic surfactants were investigated by measuring the absorption spectra of aqueous triiodide ion (I-3) solutions and surface tension. Two anionic surfactants, sodium dodecyl sulfate (SDS) and sodium 4-sulf obutyl laurate (11 C-4), were compared for their structural effects on I-3 -6 ED complex formation by mixing nonionic and anionic surfactants. The maximum absorption wavelength of I-3-6 ED shifted, and absorbance decreased in all cases with increase in the concentration of the added anionic surfactant. Two break points, A and B, were observed in a plot of maximum absorption wavelength against the anionic surfactant concentration. The slope of the plots between points A and B indicated interactions to occur between 6 ED and anionic surfactants, The SDS concentration at the points A and B was less than that of 11 C-4. Interactions of the 6 ED/SDS system were found to occur more easily than those of the 6 ED/11 C-4 system.A flat portion was observed on the surface tension curve in the 6 ED/11 C-4 mixed system, and in this portion, a mixed micelle was noted to be formed. The surface tension was found to decrease when the concentration of 6 ED was made high. In contrast, the absorbance of I-3 increased regularly, due to interaction of the 6 ED micelle with I-3, owing to the presence of 6 ED in excess. By the present I-3 solubilization method, some single 6 ED micelles and 6 ED rich mixed micelles were confirmed to be formed in the higher concentration region of 6 ED.