We demonstrated an integrated two-section phototransistor with a light-emitting transistor serving as the light source. The phototransistor optical gain can be modulated by incident optical powers and different bias conditions. With increasing incident optical power, HPTs absorb more photons and have higher internal gain than diodes.

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GaN metal-semiconductor-metal (MSM) ultraviolet (UV) photodetectors with the use of calcium fluoride (CaF2) as an insulating layer were fabricated and investigated. It was found that we can achieve a small dark current, and a large photocurrent to dark-current contrast ratio from the devices with CaF2 insulators. These results should be attributed to use of the CaF2 insulating layer, which can build a large barrier height between the metal and semiconductor.

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We demonstrate a thin film transistor-based protein sensor combined with microfluidic channel. Diffusion time and induced charge are distinguishable by various channel lengths and concentrations of IgG antibody. According to our results and theoretical calculations, an unknown concentration of IgG antibody can be obtained.

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Gas sensors for N2 detection were fabricated using carbon nanotubes (CNTs) before and after electron field emission treatment. CNTs showed an increase of sensitivity upon exposure to N2 due to CNTs provided more adsorption sites for N2 molecules after field emission treatment. The sensitivity of CNTs before and after the field emission treatment is approximately 0.12 and 0.18, respectively. Although the manipulation of field emission could increase the sensitivity, it causes permanent damages on the CNTs. In our experiment, the electrical response has been measured exposing the films to the interfering gases at different operating pressures between 50mTorr and 500Torr. Increasing detection sensitivity was observed with increasing chamber pressure. The growth process, test results, and the gas sensitivities will be discussed.

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This study focuses on systematically investigating epitaxial lift-off (ELO) speed from etching a thin layer of 150-nm sacrificial AlAs on GaAs substrate under various pattern shapes – circle, square and hexagonal. The results show the average ELO speed will be enhanced from 30 (µm/min) to 65 (µm/min) as the pattern dimension increased as well as dependent on pattern shape.

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We report on the excitation power dependent Raman scattering of undoped InAs. At a very low excitation power of 0.24 mW, the InAs shows a symmetric longitudinal optical (LO) mode with a linewidth of 3.4 cm-1, indicating its good crystallinity. However, as the power increases, an optically induced LO phonon plasmon coupled mode is observed. This LOPC mode is asymmetric and broad and hinders the measurement of the original LO mode.

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In this study,ohmic contacts were formed by e-beam evaporation of V(30 nm)/Al(200 nm)/Cr(30 nm)/Au(100 nm). These contacts were rapid thermal annealed in N2 for 30 s at various temperatures. The deposited V/Al/Cr/Au /n-AlGaN contacts at 900°C-alloyed exhibited a specific contact resistance (ρc) of approximately 3.59×10-4Ω-cm2.

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We employed ion implantation as self-assembled mask instead of dielectric materials such as SixNy or SiO2 for selective-area regrowth. This study was aimed to understand the mechanisms of selectively epitaxial growth by Metal-Organic Vapor-Phase Epitaxy(MOVPE) using Ar or Si implantation onto the surface layer of growth substrate.

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The crystalline structure and surface morphology properties of AlN films were investigated on the polycrystalline AlN substrate. The (002) prefer orientation of AlN crystal can be controlled by sputtering parameter of Ar:N2 ratio at 14:6. And the surface roughness of the poly-AlN substrate was decreased from 58.3 nm to 12.5 nm.

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Raman scattering of 3C-SiC films grown on n-type 4H-SiC substrate has been studied. Observations have been confirmed that 3C- and 4H-SiC obey the Raman selection rule of zincblende and wurtzite structures, respectively, and the LOPC mode is also recognized.

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In this study, we discussed the sensitivity of curved D-type optical fiber sensors based on the thickness of deposited gold films. The surface plasmon resonance (SPR) phenomena were observed when covering the sensing region with liquids of different refractive indices.

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We develop a scanning bad pixel replacement (BPR) algorithm with the weight analysis of neighboring pixels to improve the cluster defective pixels and enhance the image uniformity for the Quantum Well Infrared Photodetector (QWIP). Simulation results show that our proposed algorithm can significantly improve the uniformity performance of infrared images.

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A set of AlGaN films with Al content up to 62% were grown on sapphire with a low temperature AlN of several nanometers as nucleation layer. Combined variable-angle spectroscopic ellipsometer (VASE) and optical transmission (OT) data, precise optical function could be modeled.

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A ZnO-based double heterojunction structure was prepared using rf magnetron cosputtering system. A significant enhancement on the near band edge radiation with the deep level emission disappearance was measured due to the cosputtered AlN-ZnO film was both beneficial to confine theㄩelectron-hole pairs and suppress the native defects formation in i-ZnO film surface.

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In this study, the RF magnetron sputtering was used to deposit 40 nm ZnO as seed layer and insert the metal nano-Cu as the middle layer, finally the another 40nm AZO was deposed as capping layer on the glass substrate, respectively. Due to the roughened seed layer surface, which will lead the formation of nano-Cu structures and then the optoelectronic property of AZO/nano-Cu/ZnO layer had been enhanced. The results shown that the thin film has the surface of ZnO seed layer etched by 0.1wt% KOH at 150 seconds, the lower resistance of 1.3×10-4 Ω-cm was measured, and the average transmittance in visible range from 360-780 nm is about 85.5%, the best figure of merit of the ZnO(40nm)/nano-Cu(5nm)/AZO(40nm) thin film is 1.3×10-2 Ω-1.

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Uniform MoS2/graphene hetero-structures are epitaxially grown by using CVD. The film structure is examined by HRTEM. Photo-excited electron induced Fermi level shift of the graphene transistor is observed by using the hetero-structure as the channel. After rapid epitaxial process, double hetero-structures of graphene/MoS2/graphene are achieved.

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The authors reported the dependence of deposition rate in pentacene organic thin film transistors. We have obtained a specific deposition rate (0.3 Å/s) which would improve the pentacene thin-film growing property. The electronic characteristics were measured by a powerful in-situ real-time measurement system.

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Depositing selenium arsenide thin films by the pulsed laser deposition at the room temperature, and afterwards deposit gold on selenium arsenide thin films, it will form resistive random access memory (RRAM).

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This study uses the hydrothermal method to fabricate ZnO nanorods (ZnRs) array on patterned ZnO seed layers prepared by lift-off technique. The structural and optical properties of the sol-gel ZnO seed layer and the flower-like ZnRs were explored with different thicknesses of the aluminum sacrificial layer and growth time of ZnRs.

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The metal-organic-metal (MOM) ultraviolet (UV) sensors with the m-MTDATA organic layer were successfully fabricated and their low-frequency noise characteristics were also analyzed. It was found that the UV-to-visible rejection ratio of the fabricated sensor was about 28.1 when biased at 5 V with a cutoff at 220 nm. With an incident light wavelength of 220 nm and an applied bias of 5 V, it was found that measured responsivity of the sensor was 2.09x10-4 A/W. Furthermore, a lower noise level and a larger detectivity can be obtained by using m-MTDATA based UV sensors.

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The growth of single and multiple (three) ZnO/ZnMgO quantum well samples on sapphire substrates, through a two-step temperature variation growth of ZnO buffer layers by molecular beam epitaxy (MBE), were investigated. For single quantum well (QW) growth, the thicker first ZnMgO barrier layer about 220 nm on the high-temperature growth ZnO (HT-ZnO) buffer layer, accumulated larger compressive stress, to achieve higher quality ZnO/ZnMgO QW growth. In the temperature-dependent photoluminescence (PL) results, the obvious S-shape variation of emission peak positions presented the stronger exciton confinement ability of QW in the higher magnesium concentrations of ZnMgO barrier layer growth. Compared to the control sample, the quantum confinement resulted in blueshift PL peaks of QW samples at low temperature. The multiple quantum well (MQWs) structure increased the exciton confinement ability to enhance the light emission efficiency of the sample. The three ZnO/ZnMgO MQWs structures were found clearly by high-resolution transmission electron microscopy.

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Electrodeposited cuprous oxide p-n homojunction thin films were successfully fabricated for photoelectron-chemical hydrogen generation. The photocurrent response of onset potential was positively shifted and three-time enhancement of photocurrent was significantly achieved by covering n-type layer on p-Cu2O film owing to the photovoltaic effect of p-n structure.

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We investigated CdMnTe epilayers on Si(111) substrates grown by molecular beam epitaxy. Compared to CdTe epilayers, CdMnTe epilayers have better surface smoothness, crystal quality, and photoluminescence properties. Full width at half maximum of 165" in X-ray rocking curve was achieved in Cd0.63Mn0.37Te epilayer with a thickness of only 500 nm.

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In this study we have demonstrated that the improvements of detection capability of CdS photoconductors in UV regime are much larger than that in visible regime. We for the first time determined that a nanocrystallized cadmium sulfide (CdS) photoconductor can behave as a picowatt–sensitive detector in the ultraviolet (UV) regime after ultra–shallow–region crystallization of the CdS film upon a single shot from a KrF laser.

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In this paper, we use a liquid lens in a confocal laser scanning system (CLSM) for 3-D scanning. The focal length of the laser in this system can be easily changed by electrical driving the liquid lens. Thus, we can measure the distance between the sensor head and sample by detecting the reflective power according to the theory of CLSM.

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The substrate cooling technique is introduced in glancing angle deposition to sculpture Ag nanorod array(NRA). A slanted Ag NRA deposited under substrate cooling shows different optical properties compared with the other Ag NRA without cooling. A zig-zag Ag NRA is then fabricated to show near horizontal lying rods on the surface top. The associated obvious polarization dependent transmittance and reflectance spectra are then measured in this work.

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The proposal of this research was to separate the metallic and semiconducting SWNTs by agarose gel electrophoresis. There were two dispersants and two SWNTs: Triton X-100 & SDS and SWNTs with and without acid, respectively. The optimum separation of semi- and metal- SWNTs was used Triton X-100 with acid SWNTs.

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In this study, we demonstrated a full-field heterodyne interferometer to determine the phase variation of the glucose oxidase (GOx) enzyme with various reaction activity. According to the measurement results, the phase variation was inversely proportional to the applications of GOx.

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IPMC (Ionic Polymer Metallic Composite) is used as a deformable mirror for focus tuning. In this paper we changed the electrode of the IPMC from platinum to silver. With the lower Young’s modulus and lower surface resistivity of silver, we can decrease the driving voltage from 3V to almost 2V. The shortest focal length is 6.5 mm.

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A simple and low-cost technique is proposed to construct a tunable liquid crystal beam steering with polymer wedge structure by micro-drop technology and polymerization. The geometric profile of the polymer wedge depends on the microdroplet volume and UV irradiation dose. The deflection angle can be electrically tuned from 0°to 5°.

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Nb2O5-SiO2 composite films were prepared by fast-alternative bipolar-pulsed magnetron sputtering using niobium oxide and silicon targets. The influence of thermal annealing on optical properties and stress behaviors of composite films were investigated by spectroscopic ellipsometer and phase-shift Twyman-Green interferometer.

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An improved approach for measuring the residual stress in thin films by substrate contour subtraction is presented. We proposed a Twyman-Green interferometer combined with fast Fourier transform (FFT) and contour subtraction method to measure the residual stress of thin films. The results show that the deviation of measuring values is significantly reduced in residual stress measurement of thin films.

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The Niobium Oxide thin films were deposited by DC- ,and high power pulsed reactive magnetron sputtering. The influence of thermal annealing on refraction indices, extinction coefficients and surface roughness of NbOx films were analyzed via spectroscopy and atomic force microscope.

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The purpose of this work is to study the anti-reflection coating structure with spherical SiO2 micro particles for the single-crystalline silicon solar cell applications. With the spherical SiO2 micro particles, the surface reflectivity of the single-crystalline silicon substrate can be reduced to an average value of 5.8% in the 400 – 700 nm wavelength range.

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