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In this study, Eu-doped Li2 (Ba1-x Srx )SiO4 powders (x = 0, 0.2, 0.4, and 0.6) were synthesized at 850°C in a reduction atmosphere (5% H2 + 95% N2 ) for a duration of 1 h using a solid-state reaction method. The reduction atmosphere was infused as the synthesis temperature reached 850°C, and was removed as the temperature dropped to 800-500°C. Li2 (Ba1-x Srx )SiO4 (or Li2 BaSiO4 ), (Ba,Sr)2 SiO4 (or BaSiO4 ), and Li4 SiO4 phases co-existed in the synthesized Eu-doped Li2 (Ba1-x Srx )SiO4 powders. A new finding was that the reduction atmosphere removing (RAR) temperature of the Li2 (Ba1-x Srx )SiO4 phosphors had a large effect on their photoluminescence excitation (PLE) and PL properties. Except for the 800°C-RAR-treated Li2 BaSiO4 phosphor, PLE spectra of all other Li2 (Ba1-x Srx )SiO4 phosphors had one broad emission band with two emission peaks centred at ~242 and ~283 nm; these PL spectra had one broad emission band with one emission peak centred at 502-514 nm. We showed that the 800°C-RAR-treated Li2 BaSiO4 phosphor emitted a red light and all other Li2 (Ba1-x Srx )SiO4 phosphors emitted a green light. Reasons for these results are discussed thoroughly.

A new composite nanostructure, placing two circle Ag nanoparticles (NPs) on the surface of a SiO2 ellipsoid nanoparticle (abbreviated as AgNPs@SE), was established to analyze the extinction spectra using finite-difference time-domain (FDTD) method. We would show that the new constructed AgNPs@SE nanostructure had exhibited better extinction performance as compared to an isolated NP. Furthermore, we would optimize the performance by tuning structural parameters of the constructed AgNPs@SE nanostructure, including the angle of Ag NPs and aspect ratios of SiO2 ellipsoid NP. We could prove that the constructed nanostructure with the end-to-end orientation model of the AgNPs@SE nanostructure had existed exciting hot spot. Moreover, the array of multimer was also constructed for further investigation. This work could helpful for the design of the AgNPs@SE multimer nanostructure, which can be used to assist photo-catalysis and surface-enhanced Raman spectroscopy (SERS).

Compositions of [Formula: see text] and [Formula: see text] were mixed and sintered at 1250[Formula: see text]C to fabricate [Formula: see text] and [Formula: see text] targets, and RF sputtering method was used to deposit [Formula: see text] and [Formula: see text] films by introducing pure Argon during the deposition process. After [Formula: see text] and [Formula: see text] films were deposited, we used the X-ray diffraction pattern to analyze their crystalline properties, the ultraviolet–visible-infrared spectrophotometry to measure their transmittance spectra in the wavelength range of 200–800 nm, an X-ray photoelectron spectroscopy to find their composition variation, and a Hall equipment to measure their electrical properties, including the carrier concentration, the mobility, and the resistivity. We found that the absorption edges of [Formula: see text] films were shifted to higher wavelength as [Formula: see text] value increased from 0.2 to 0.4. We also found that the Hall parameters of [Formula: see text] film could not be measured because of its high resistivity. Therefore, [Formula: see text] film was used to fabricate thin-film transistor (TFT), and the electrical properties of the fabricated TFT were also well investigated.

We report a metal-insulator-semiconductor (MIS) diode with an α-Ga 2 O 3 thin-film insulator layer grown by liquid-phase deposition (LPD). α-Ga 2 O 3 exhibits a high energy bandgap of 4.9–5.3 eV, which can effectively reduce the leakage current density and improve the breakdown voltage of the diode. The α-Ga 2 O 3 thin films are synthesized from GaOOH with LPD. The α-GaOOH crystal is simply obtained by the dissociation of the Ga(OH) 3 precursor solution. GaOOH can be transformed into α-Ga 2 O 3 crystal and form a uniform thin film following post-growth annealing. When the α-Ga 2 O 3 thin film is inserted in between Ni and Si to form a Ni/α-Ga 2 O 3 /Si MIS diode, the barrier height of the diode increases by 0.4 eV and the on/off ratio by 100-fold from those of the Ni/Si Schottky diode. The Ni/α-Ga 2 O 3 /Si MIS diode exhibits a leakage current density of 1.07 × 10 −5 A/cm 2 under −2 V bias. The breakdown voltage of the diode reaches −166 V without the guard ring and other insulation structures. Our results demonstrate that LPD-grown α-Ga 2 O 3 thin films can obtain uniform and dense structure under short deposition time and at an annealing temperature of 400 °C. The uniform insulating layer of α-Ga 2 O 3 has a high potential in enhancing the electrical characteristic of diodes and other power electronic devices.

In this study, Eu-doped Li

Single-phase Au nanorods were synthesized using an anodic alumina oxide (AAO) template for methyl mercaptan (CH3SH) gas detection. The Au nanorods were fabricated by pulse electrodeposition on a H2O2 modified template. A Au precursor solution was modified with dimethyl sulfoxide to improve the synthesis of Au nanorods. The deposition parameters of the duty cycle were modulated in multiple groups to produce high-quality Au nanorods. Scanning electron microscopy images illustrated the high regularity of the Au nanorods. X-ray diffraction and transmission electron microscopy images revealed the high composition of the (111) lattice interface. A Au nanorod gas sensor was fabricated after removal of the AAO template. The sensor utilized the self-assembled monolayer property between Au and CH3SH to alter the conductivity of the Au nanorod sensing layer. The sensor exhibited higher sensitivity and selectivity to CH3SH than to N2 and H2S. The sensor had a 0.88% current response under a 0.5 ppm concentration of CH3SH, which increased to 7.82% under 4 ppm CH3SH. The Au nanorods possessed a response 13 times higher than that of a Au thin-film structure.

The purpose of this research is to investigate a low-cost liquid-phase deposition (LPD) method for preparing gallium oxide ([Formula: see text]-Ga2O[Formula: see text] films. This approach has the advantages of being easy and not requiring a vacuum, and it is suitable for large-area manufacturing. First, the LPD method was used to precipitate GaOOH particles below a pH of 8 and at 80[Formula: see text]C; these were used as the precursor for the gallium oxide ([Formula: see text]-Ga2O[Formula: see text] films. Ammonium fluoride (NH4F) with concentrations of 0.1, 0.3, and 0.5 M was added to the solution to form fluorine-doped (F-doped) GaOOH. The precipitated F-doped GaOOH powders were analyzed using an energy-dispersive X-ray spectroscopy (EDS) on a field emission scanning electron microscope to identify elemental F, Ga, and O. We found that the concentration of F ions increased with the NH4F concentration. The deposited films were then annealed at 900[Formula: see text]C for 4 h to transform the F-doped GaOOH into F-doped [Formula: see text]-Ga2O3. EDS was used to analyze the F-doped [Formula: see text]-Ga2O3 films, and we found that their F[Formula: see text] ion concentration also increased with the NH4F concentration. XPS analysis was used to confirm the existence of F[Formula: see text] ions in the F-doped [Formula: see text]-Ga2O3 films. The analyzed results also showed that as the NH4F concentration increased, the electrical performance of F-doped gallium oxide improved. Finally, the F-doped [Formula: see text]-Ga2O3 films were used to fabricate F-doped [Formula: see text]-Ga2O3/p[Formula: see text]-Si junction diodes, and their J–V properties were thoroughly investigated. We found that the rectification characteristics of the F-doped [Formula: see text]-Ga2O3/p[Formula: see text]-Si diodes could be significantly improved.

This study revealed the band gap, visible transmittance, and crystallinity variation Cd1 − x S:B emitter layer at different boron concentrations, as well as the CuInSe2 absorption layer nucleation mechanism at pH values ranging from 1.53 to 2.13. CuInSe2 deposited at a pH of 1.73 showed the highest grain size (24.29 nm) and approached the stoichiometric state of [Cu]/[In] = 0.98, which produced was used for solar cells and Schottky diode. The conversion efficiency of Al/AZO/Cd1 − xS:B/CuInSe2/Mo/Glass structure cell was 2.37% (Voc: 293 mV, Jsc: 26.85 mA/cm2, and FF: 0.301). Moreover, the aluminum material were deposited on CuInSe2 as a Schottky diode (Al/CuInSe2/Mo/Glass), which diode was used to estimate the work function (Φ) and ideality factor (n) through Schottky barrier. These device parameters of Al/CuInSe2 structure was ΦCuInSe2 = 4.791 eV and n = 3.52, respectively. This result revealed that the Cd1 − xS:B/CuInSe2 interface state can cause Fermi-level pinning with an interface recombination velocity of 2.328 × 103 cm s− 1. This indicates the poor performance of Schottky diodes and thin film solar cells comprising Cd1 − xS:B/CuInSe2. However, experimental results demonstrated that the passivation of the surface by using iodine treatment can improve the Fermi-level pinning effect on Cd1 − xS:B/CuInSe2 interfaces.

Copper indium selenide (CuInSe 2 ) nanowire (NW) arrays were prepared at various electrolyte duty cycles by filling anodic alumina templates through the pulsed electrodeposition technique. X-ray diffraction and scanning electron microscopy (SEM) images showed that the nucleation mechanism of CuInSe 2 NW arrays was affected by the electrodeposition duty cycle. Moreover, SEM images showed that the diameter and length of the NWs were 80 nm and 2 μm, respectively. Furthermore, PEDOT/CuInSe 2 NW core–shell arrays were fabricated using surfactant-modified CuInSe 2 NW surfaces showing the lotus effect. Transmission electron microscopy images confirmed that a core–shell structure was achieved. Current–voltage plots revealed that the CuInSe 2 NW arrays were p-type semiconductors; moreover, the core–shell structure improved the diode ideality factor from 3.91 to 2.63.

CuInSe2 nanowire (NW) arrays were prepared in a heated electrolyte (45°C) through anodized aluminum oxide template–assisted pulse electrodeposition. After the CuInSe2 NWs were as-grown, grazing incidence X-ray diffraction and high-resolution transmission electron microscopy (HRTEM) revealed the recrystallization status of the CuInSe2 NWs annealed at temperatures ranging from 250°C to 550°C. The results indicated that the NWs underwent a phase transformation from the (204/220) plane to the (112) plane. Additionally, the material particle size and quantum dots were measured using HRTEM and ultraviolet/visible spectroscopy. The particle size of the as-grown CuInSe2 NWs ranged from 3.8 to 8 nm. The as-grown CuInSe2 NWs exhibited a blue-shift in the material absorption band at 1100 and 1200 nm compared with those annealed at 550°C. The results of scanning electron microscopy had a diameter and length of 80 nm and 2.2 μm, respectively. Mott–Schottky and ohmic contact plots revealed that the CuInSe2 NWs were p-type semiconductors. Moreover, the different leakage current mechanisms of the nonideal Schottky diode were studied. Finally, near-ideal Schottky barrier diodes were obtained at an annealing temperature of 550°C, and their work function was estimated to be in the range of 5.04–5.13 eV.

At first, Cr-Si (28 wt% Cr, 72 wt% Si) and Ni-Cr (80 wt% Ni, 20 wt% Cr) thin-film materials were deposited by using sputtering method at the same parameters, and their physical and electrical properties were investigated. The resistances of Cr-Si and Ni-Cr thin-film resistors decreased with the increase of deposition time (thickness) and their resistivity had no apparent variations as the deposition time increased. The temperature coefficient of resistance (TCR) of single-layer Cr-Si thin-film resistors was negative and the TCR value of single-layer Ni-Cr thin-film resistors was positive. For that, we used Cr-Si thin films as upper (or lower) layer and Ni-Cr thin films as lower (upper) layer to investigate a bi-layer thin-film structure. The deposition time of Ni-Cr thin films was fixed at 10 min and the deposition time of Cr-Si thin films was changed from 10 min to 60 min. We had found that as Cr-Si thin films were used as upper or lower layers they had similar deposition rates. We had also found that the thickness and stack method of Cr-Si thin films had large effects on the resistance and TCR values of the bi-layer thin-film resistors.

This letter proposes the use of carbon black film in absorbing high-frequency power. This low-cost material can be obtained easily using a low-cost fabrication process (i.e., screen printer). The 70 wt% carbon black film is 0.055-mm thick, with sheet resistance of $162~\Omega $ /sq and conductivity of 113.6 S/m. Results show that carbon black film absorbs high-frequency signal, and the power loss reaches 70% at 3 GHz. Moreover, the starting suppression frequency could be controlled by adjusting the proportion of carbon black.

In this study, CuInSe2 (CIS) films (CIS-TFs) and nanorods (CIS-NRs) were successfully deposited on Mo/glass and p+-silicon (p+-Si) using an electrodeposition method. Anodic aluminum oxide (AAO) was used as the template when the CIS-NRs were deposited. Pt, indium tin oxide (ITO), and Ag were deposited as the upper electrodes using a sputtering method to form the hetero-junction devices of Pt/CIS-NRs/p+-Si, ITO/CIS-NRs/p+-Si, ITO/CIS-TF/Mo/glass, and Ag/CIS-NRs/p+-Si, respectively. When p+-Si was used as the substrate, Al was deposited on p+-Si to form negative electrodes for the devices of Pt/CIS-NRs/p+-Si, ITO/CIS-NRs/p+-Si, and Ag/CIS-NRs/p+-Si. The current&ndash, voltage properties of all the hetero-junction devices were measured and we found that the hetero-junction of ITO/CIS-NRs/p+-Si, ITO/CIS-TF/Mo/glass, and Ag/CIS-NRs/p+-Si devices revealed the properties of Schottky diodes but the hetero-junction device of Pt/CIS-NRs/p+-Si device did not. The reason for the cause of the differences between these hetero-junction devices was investigated for this study.

In this paper, Al-doped ZnO (AZO) films are deposited on glasses substrate by RF magnetron sputtering. The optical, electrical and morphological properties of AZO films textured by wet-etching with different etchants, H3PO4, HCl, and HNO3 are studied. It is found that the textured structure could enhance the light scattering and light trapping ability of amorphous silicon solar cells. The textured AZO film etched with HNO3 exhibits optimized optical properties (T% ≧ 80% over entire wavelength, haze ratio > 40% at 550 nm wavelength) and excellent electrical properties (ρ = 5.86 × 10−4 Ωcm). Scanning electron microscopy and Atomic force microscopy are used to observe surface morphology and average roughness of each textured AZO films. Finally, the textured AZO films etched by H3PO4, HCl and HNO3 were applied to front electrode layer for p–i–n amorphous silicon solar cells. The highest conversion efficiency of amorphous silicon solar cell fabricated on HNO3-etched AZO film was 7.08% with open-circuit voltage, short-circuit current density and fill factor of 895 mV, 14.92 mA/cm2 and 0.56, respectively. It shows a significantly enhancement in the short-circuit current density and conversion efficiency by 16.2% and 20.2%, respectively, compared with the solar cell fabricated on as-grown AZO film.

This paper proposes Ag–Fe3O4 films as a novel noise absorption material for the microstrip transmission line to replace current magnetic materials. The effect of the Ag–Fe3O4 films on a microstrip transmission line for high-frequency noise absorption is discussed. Ag–Fe3O4 films were prepared using the spin-coating technique and deposited on FR4 substrates. The film thickness was approximately 25–75 $\mu \text{m}$ and sheet resistance was controlled in the range of 450–150 $\Omega $ . Crystal structures of Ag–Fe3O4 films were conducted using the X-ray diffraction technique. The radio frequency properties of these films were measured using an Agilent Technologies E8364A vector network analyzer in the frequency range of 1–20 GHz. The experimental results show that the composite sheet in the broadband frequency region effectively absorbs the electromagnetic noise, exhibiting a power loss greater than 70% in the frequency range of 6–20 GHz.

This study confirms that a LiF/Al (LiF thickness = 15 A) stack is an efficient Ohmic contact method for use in p-Ni1 − xO:Li/n-Si heterojunction solar cell applications. The maximal conversion efficiency obtained was 6.31%, which was 2.1% greater compared with that of Al-only electrode cell. Temperature-dependent current–voltage measurements confirmed that the carrier transport mechanism was dipole-assisted tunneling at the interface. The insertion of LiF acted as an effective Ohmic contact method and also assisted the back surface passivation.

As a result of the growing use of wireless communication devices, high-frequency noise issues are becoming increasingly important. In this study, a graphene film is utilized as a high-frequency power absorber. Epoxy is mixed with the graphene to adjust its conductivity. The graphene film is deposited onto a microstrip line of FR4 substrates via screen printing technology. Experimental results show that graphene film is with a sheet resistance of 114 Ω/sq and a conductivity of 973 S/m and its power loss reaches 70% at 1.35 GHz.

We prepared CuInSe 2 nanowire (NW) arrays in an electrolyte at temperatures ranging from 272 K to 318 K by using pulse electrodeposition techniques and an anodized aluminum oxide template. We photographed the detailed microstructures of CuInSe 2 nanowire arrays with high-resolution transmission electron microscopy (HRTEM); the images showed the polycrystalline nature of the CuInSe 2 nanowires made in electrolyte at a temperature of 318 K. The results of X-ray diffraction and scanning electron microscopy showed that the electrodeposition temperature constrained the CuInSe 2 NW nucleation mechanism.

This study investigates the effects of sputtering power on the performance of p-Ni1−xO:Li/n-Si heterojunction solar cells (HJSCs). The results of this study indicate a strong dependence of the cell characteristics on the sputtering power. Extremely high or low sputtering power generates higher interface state density (D it ), resulting in the lowering of open circuit voltage (V oc ) and fill factor (FF). The cell fabricated at a sputtering power of 100 W has the lowest D it of 7.08 × 1011 cm−2 eV−1, corresponding to the highest conversion efficiency (η) of 4.30 % [short circuit current density (J sc ): 18.06 mA cm−2, V oc : 390 mV, FF: 61.1 %, series resistance (R s ): 4.3 Ωcm2 and shunt resistance (R sh ): 478.75 Ωcm2]. Furthermore, the cell exhibits a considerably poor temperature coefficient of −0.70 %/ °C (J sc : +0.07 %/°C, V oc : −0.52 %/°C and FF: −0.29 %/°C) when compared with conventional solar cells. Further improvement in the D it of the cell is highly imperative for developing p-Ni1−xO:Li/n-Si HJSCs with a high conversion efficiency and a good temperature coefficient.

We conducted a chronoamperometric study to observe the electrochemical behaviors of the nucleation mechanism of electrodeposited Cu(In,Al)Se 2 films. A change from instantaneous nucleation to progressive nucleation was observed by increasing the copper concentration. SEM and EDS analyses demonstrated that the surface morphologies and chemical compositions of precursor and post-annealed Cu(In,Al)Se 2 films were influenced by the nucleation mechanism. They exhibited that Cu(In,Al)Se 2 films had roughly cauliflower-like and triangular structures with Cu-poor composition at the instantaneous nucleation mechanism, whereas smooth and round structures with Cu-rich composition at the progressive nucleation mechanism. Additionally, the quality, growth orientation, composition phase, and optical energy band gap of Cu(In,Al)Se 2 films were examined using X-ray diffraction (XRD) patterns, Raman spectra, and ( αhν ) 2 vs. hν plots (UV–vis). Thereafter, the performances of rudimentary Cu(In,Al)Se 2 solar cells fabricated at various copper concentrations were discussed, the conversion efficiency of electrodeposited Cu(In,Al)Se 2 solar cells were unpublished in previous literatures. Our studies demonstrated that the performances of Cu(In,Al)Se 2 solar cells were significantly related to the surface morphology and composition of Cu(In,Al)Se 2 absorber layer. The highest conversion efficiency of Cu(In,Al)Se 2 solar cells fabricated at a 2-mM copper concentration was 1.96% with open-circuit voltage, short-circuit current, fill factor, R sh and R s values of 0.189 V, 29.21 mA/cm 2 , 35.4%, 125 Ω and 2.82 Ω, respectively.

The purpose of this study is to reduce textured crystalline silicon (TCS) substrate surface-reflectivity over a wide spectral range (300–1100 nm), to improve the step coverage of the textured structure, and to shift the minimal value of reflection from the unabsorbed region to the absorbed region. The TCS solar-cell interface between air and silicon was added to a SiO x /SiO x N y /SiN x triple-layer anti-reflective coatings (TLARCs) structure using the plasma-enhanced chemical vapor deposition (PECVD) growth method. This paper presents theoretical and practical discussions, as well as the experimental results of fabricating the films and devices. The average reflection of the SiO x /SiO x N y /SiN x TLARs reduced to 2.01% (300–1100 nm). The minimal value of reflection was shifted from 1370 nm (unabsorbed region) to 968 nm (absorbed region). The SEM images show effective step coverage. In comparison to the untreated TCS solar cells, applying the experimental SiO x /SiO x N y /SiN x TLARCs to conventional TCS solar cells improved the short-circuit current density ( J sc ) by 7.78%, and solar-cell efficiency by 10.95%. This study demonstrates that the SiO x /SiO x N y /SiN x TLARCs structure provides antireflective properties over a broad range of visible and near-infrared light wavelengths. An effective step coverage and minimal value of reflection from unabsorbed region shift to the absorbed region is demonstrated.

Cu-poor electrodeposited CuIn1−xAlxSe2 (CIAS) precursor films were prepared to investigate the alteration in surface morphology of post-annealed CIAS films through post-annealing temperature adjustment. Scanning electron microscopy (SEM) and atomic force microscope (AFM) analyses demonstrated that surface morphology and root–mean–square (RMS) roughness of post-annealed CIAS films exhibited uneven and rough triangular structures. The crystal size of post-annealed CIAS films can be increased by increasing post-annealing temperature. The precursor film structure was modified by substituting Cu–Se/CIAS binary structure with CIAS single structure to proceed with the investigation. The apparent variation in surface morphology of post-annealed CIAS films changed from rough triangular structures to smooth round structures, and the RMS roughness of post-annealed CIAS films was reduced to

CuInSe2 thin films were prepared on Mo-coated glass substrates using pulse electrodeposition with an aqueous solution containing sodium dodecyl sulfate (SDS) as an additive. The effect of SDS on the electrochemistry mechanism that inhibits secondary phases (CuxSey) was examined using cyclic voltammetry, which indicated that SDS can inhibit the reduction of Cu2+ and H2SeO3 and prohibit the formation of secondary phases. Scanning electron microscopy and atomic force microscopy revealed that the cracks and roughness of CuInSe2 films decreased considerably after adding SDS into the electrolyte. The suppression of secondary phases was also observed using X-ray diffraction and Raman spectroscopy. The optical bandgap values of the CuInSe2 films were measured using a UV–vis–NIR spectrophotometer; the bandgap values of the films deposited in the electrolyte with 0 and 1 mM SDS were approximately 0.96 and 1.05 eV, respectively. As expected, based on these differences, the CuInSe2 solar cell with the Al/AZO/i-ZnO/CdS/CuInSe2/Mo/glass structure derived from precursor film deposited in an electrolyte containing SDS demonstrated greater efficiency (η = 2.51 %) than that of the cell derived from precursor film deposited in an electrolyte without SDS (η = 0.63 %).

This study confirms that the surface texturation of window layer (Al-Y codoped ZnO) etched by diluted HCl effectively increases conversion efficiency of p-Ni1−xO:Li/n-Si heterojunction solar cells. The results show that the short circuit current density (Jsc) of cell etched at 10 s increases about 8.5% compared to unetched cell, which also corresponds to the increase of efficient photoelectric conversion in NIR region as shown in external quantum efficiency spectra. It is attributed to the increase of light transmittance of AZOY thin films in the NIR region and the effective light path of the NIR wavelength, which results in increasing of light absorption in the base layer.

A novel compact multiband planar antenna fed by a microstrip line structure is presented. The proposed antenna is developed for wireless communication applications of the global system for mobile (GSM) communication and long-term evolution (LTE) in different service bands of 900, 1800, 1900, 2300, and 2500 MHz. The antenna has five bands, and the structure is a combination of a monopole antenna and a coupled ground line fabricated on an FR4 substrate. The proposed antenna can be embedded in mobile phones for GSM and LTE applications. The measured peak gains are ∼2.12 and 3.82 dBi for the GSM and LTE bands, respectively.

This letter proposes a novel method of designing wideband bandpass filters (BPFs) that contain high-frequency harmonic suppression. Ag- ${\rm Fe}_{3} {\rm O} _{4}$ films are used as harmonic suppression materials in such filters to replace the current general suppressing circuits. The wideband BPF can be designed using distributed highpass filters are equipped with two short-circuited stubs, and Ag- ${\rm Fe}_{3} {\rm O} _{4}$ films are combined with the harmonic suppression mechanism. Several high-order harmonic resonance bands may be suppressed using a wide stopband by adjusting the thickness of the Ag- ${\rm Fe}_{3} {\rm O} _{4}$ films appropriately. The stopband of the proposed wideband BPF is extended to 20 GHz, which result in a rejection level higher than 15 dB.

Low cost transparent conductive Al–Y codoped ZnO (AZOY) thin-films were prepared on a glass substrate using a DC magnetron sputtering technique with various working pressures in the range of 5–13 mTorr. The relationship among the structural, electrical, and optical properties of sputtered AZOY films was studied as a function of working pressure. The XRD measurements show that the crystallinity of the films degraded as the working gas pressure increased. The AZOY thin-film deposited at a working pressure of 5 mTorr exhibited the lowest electrical resistivity of 4.3 × 10 −4 Ω cm, carrier mobility of 30 cm 2 /V s, highest carrier concentration of 4.9 × 10 20 cm −3 , and high transmittance in the visible region (400–800 nm) of approximately 90%. Compared with Al doped ZnO (AZO) thin-films deposited using DC or RF magnetron sputtering methods, a high carrier mobility was observed in our AZOY thin-films. This result can be used to effectively decrease the absorption of near infrared-rays in solar cell applications. The mechanisms are attributed to the larger transition energy between Ar atoms and sputtering particles and the size compensation of the dopants. Finally, the optimal quality AZOY thin-film was used as an emitter layer (or window layer) to form AZOY/n-Si heterojunction solar cells, which exhibited a stable conversion efficiency ( η ) of 9.4% under an AM1.5 illumination condition.

In this study we used a novel process, involving advanced lithography and oxygen plasma treatment to generate well-defined 400 nm-resolution hole array. 400 nm pillar array of polystyrene (PS) on silicon surface was successively grafted from the bottom layer of initiator by atom transfer radical polymerization (ATRP) to generate two-dimensional periodic relief grating (2DPRG). The 2DPRG of the tethered PS after immersion in solvents possessing various polarities present solvent-responsive properties in static water contact angles (SWCAs) and effective refractive indices (neff) because of transition between stretched and coiled regime of the polymer. The neff of the 2DPRG of tethered PS after immersion in water and toluene are 1.46 and 1.39 resulting of red and green color observed along an oblique angle closed to 60° ∼ 70° by naked eye, respectively. These reversibly properties created from a reversible conformational change of 2DPRG of tethered PS exhibited switching property in change of solvent polarity which is practical for environment sensor applications.

This paper proposes anodic aluminum oxide (AAO) on a 20 cm × 20 cm tin-doped indium oxide (ITO)/glass substrate by using an anodization process with a specially designed carrier. The proposed AAO can be used at a high applied bias (>110 V) to improve the uniformity of current density. The enhancement of light transmittance is observed by modulating the porous diameter. Therefore, the increased transmittance of AAO/ITO/glass with increased time of pore-widening treatment is attributed to the decreased refractive index of AAO film. By using pore-widening and post-annealing treatments, the morphologies and optical transmission spectra of AAO/ ITO/glass were also examined.

In this study we developed an efficient method for the direct patterning of Au, through the self-assembly of gold nanoparticles (AuNPs) from colloidal solutions, onto Si substrates. We used an integrated process involving soft lithography and self-assembly to fabricate patterns of sub-micrometer AuNPs on the Si surface. By exploiting soft lithography, we obtained nanoscale patterns of self-assembled monolayers (SAMs) without the need for traditional photolithography or etching processes. After using soft lithography to pattern a SAM of (3-mercaptopropyl)trimethoxysilane on a Si surface, we immobilized AuNPs, synthesized in a two-phase system, to form the bottom layer. We then used a cross-linking agent, 1,6-hexanedithiol, to construct multiple layers of AuNP aggregates, ultimately self-assembling five-layer structures that we employed as nanoscale metal electrodes in the fabrication of organic field effect transistors (OFETs), which exhibited output characteristics, including sheet resistance, drain–source voltage, and drain–source current, similar to those of corresponding OFETs prepared using traditional processing.

In this study, commercial-grade NiCr (80 wt % Ni, 20 wt % Cr) and NiCrSi (55 wt % Ni, 40 wt % Cr, 5 wt % Si) were used as targets and the sputtering method was used to deposit NiCr and NiCrSi thin films on Al2O3 and Si substrates at room temperature under different deposition time. X-ray diffraction patterns showed that the NiCr and NiCrSi thin films were amorphous phase, and the field-effect scanning electronic microscope observations showed that only nano-crystalline grains were revealed on the surfaces of the NiCr and NiCrSi thin films. The log (resistivity) values of the NiCr and NiCrSi thin-film resistors decreased approximately linearly as their thicknesses increased. We found that the value of temperature coefficient of resistance (TCR value) of the NiCr thin-film resistors was positive and that of the NiCrSi thin-film resistors was negative. To investigate these thin-film resistors with a low TCR value, we designed a novel bi-layer structure to fabricate the thin-film resistors via two different stacking methods. The bi-layer structures were created by depositing NiCr for 10 min as the upper (or lower) layer and depositing NiCrSi for 10, 30, or 60 min as the lower (or upper) layer. We aim to show that the stacking method had no apparent effect on the resistivity of the NiCr-NiCrSi bi-layer thin-film resistors but had large effect on the TCR value.