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To improve the performance of optoelectronic devices, a high performance wide angle SiO2/Ti3O5 Distributed Bragg Reflector (DBR) mirror was designed and fabricated on double polished sapphire substrate. 17-pairs gradually varied DBR structure was applied in order to acquire a broad stopband reflectivity over 95% from 400 nm to 800 nm, covering the whole visible light region. The DBR mirrors deposited at the backside of optoelectronics devices are also demonstrated to remain a high reflectivity at wide incident angles, which improves the emission efficiency of LEDs and light absorption efficiency of InGaN/GaN photoelectrochemical cell (PEC).

A strong coupling effect often occurs between a metal and semiconductor, so micro/nano-lasers based on surface plasmons can break through the optical diffraction limit and realize unprecedented linear and nonlinear enhancement of optical processes. Hence, metal–insulator–semiconductor (M–I–S) structures based on perovskite materials were explored to design optoelectronic devices. Herein, we constructed an Ag/SiO2/CsPbBr3 hybrid structure to generate surface plasmon coupled emission between the metal and CsPbBr3 perovskite. Combined with experimental characterization and COMSOL Multiphysics software simulations, the best enhancement for CsPbBr3 radiative recombination efficiencies can be achieved with a 10 nm-thickness of the SiO2 layer and 80 nm-thickness of the Ag metal film, further verified by optimizing the thickness of the SiO2 layer above the Ag metal film. In this state, the laser threshold can be as low as 0.138 μW with a quality (Q) factor of up to 3907 under optical pumping, which demonstrate a significant step toward practical applications in biological technology, chemical identification, and optical interconnections of information transmission.

High-entropy oxides (HEOs), due to their excellent physicochemical properties, have attracted extensive attention. In this work, the solution combustion synthesis approach was applied to prepare a series of porous single-phase HEO nanocrystalline powders. Equiatomic (Co0.2Cu0.2Mg0.2Ni0.2Zn0.2)O, (Cr0.2Fe0.2Mn0.2Mg0.2Zn0.2)3O4 and (Ce0.2La0.2Pr0.2Sm0.2Y0.2)O2 were successfully obtained. While the former two could be stabilized into single rock-salt (Fm-3m) and spinel (Fd-3m) structures, the latter could be synthesized to have either CaF2-type (Fm-3m) or CaF2-related-type (Ia-3) structure depending on synthesis temperature. Furthermore, their chemical and microstructural homogeneity was further confirmed.

Semi-polar micro-LEDs have gain increasing interests due to the advantages of polarization control and quantum efficiency improvement. In this work, a novel semi-polar (20–21)-plane micro-LEDs array has been designed and manufactured. In comparison with c-plane micro-LEDs, semi-polar micro-LEDs indicate better electrical and optical performance. The relative EQE of semi-polar micro-LEDs remains at 62% under the injected current density of 775.6 A/cm2, which indicates a reduced efficiency droop due to less polarization in MQWs. It has been further proved by a significant reduction of 55% in emission peak blue-shift under the injected current density from 11.1 A/cm2 to 775.6 A/cm2. In addition, the carrier recombination dynamics and spatial light distribution of semi-polar micro-LEDs with different pixel sizes have been studied. Fast recombination lifetime in smaller size semi-polar micro-LEDs indicates a promising way to be used as a high modulation bandwidth light source. Stable and uniform light distribution in a wider range of spatial azimuths further supports for the semi-polar micro-LEDs as a strong candidate for the applications of high-resolution display and high-speed visible light communication.

Current-voltage ( I-V ) characteristics of AlGaN ultraviolet light-emitting diodes (UV-LEDs) under the temperatures ranging from 50 K to 300 K are analyzed. The abnormal diode characteristics of UV-LEDs below the turn-on voltage indicate the existence of space-charge-limited (SCL) current transport in the presence of deep trap states, which induce a non-linear current leakage effect. The SCL current is gradually overwhelmed by Ohmic leakage as the temperature increases, which is mainly due to the thermally generated carrier concentration and traps deactivation. A modified three-diode circuit model is suggested with an additional series resistor and diode to emulate the forward-bias I-V characteristics of UV-LEDs. An excellent fit to the I-V curves of UV-LEDs is achieved, which illustrates the impact of deep trap states on the electrical characteristics of UV-LEDs.

Tunneling field-effect transistors (TFETs) based on two-dimensional (2D) materials are expected to break the physical limits of Moore's Law and extend them to the sub-10 nm scope. We systematically study the performance limits of sub-10 nm (6.4-9.6 nm) monolayer (ML) AsP TFETs by means of ab initio quantum transport calculation. With optimized doping, ML AsP TFETs show excellent performance in the armchair transport direction, which is satisfied the requirements of the International Technology Roadmap for Semiconductors (ITRS) and the International Roadmap for Devices and Systems (IRDS 2028 projection) for high-performance (HP) applications in the next ten years in terms of on-state current, delay time, and power consumption per wide power. More encouragingly, ML AsP TFET can still meet the goal of ITRS for low-power (LP) applications even if the gate length is scaled down to 8.7 nm. The on-state current of our proposed AsP TFET is superior to that of TFETs based on InAs, arsenene, antimonene, bismuthene, etc at approximate nodes, making it highly competitive in two-dimensional material semiconductor devices.

Hybrid white light emitting diodes (LEDs) have been developed utilizing micro-LEDs radiatively pumping down-conversion phosphor materials. The cyan InGaN/GaN multiple quantum wells LEDs with 95 μm in square are fabricated into 4 × 4 pixels as one unit in 4 in wafer by photolithography and inductively coupled plasma etching techniques. The relatively low turn on voltage and low leakage of cyan micro-LEDs indicate good electrical performance. A significant reduction in the efficiency droop characteristics of cyan micro-LED has been observed in comparison with that of standard green LED. Finally, based on a systemic optimization for white emission indexes, high-quality hybrid white light emission has been demonstrated by the combination of blue and cyan micro-LEDs with two types of phosphors, which have a high color rendering index up to 87 at the correlated color temperatures of 6500 K. It also demonstrates a way to adjust the color component by modifying the output power of cyan micro-LED in hybrid LED, showing a promising candidate in a large range of applications including micro-displays, bioinstrumentation, photolithography, and lab-on-chip systems in the future.

ZnO nanocrystals were prepared using three different salts of ZnSO4, Zn (CH3COO)2and Zn (NO3)2by chemical bath deposition. The samples were characterized by XRD, SEM, PL, and FTIR spectroscopy. The XRD results showed that all the samples exhibit the hexagonal wurtzite standard crystal of ZnO. When the zinc precursor is ZnSO4and Zn (CH3COO)2, B1 and A2 possess the best crystallinity. The FESEM results showed all the samples have flower-like ZnO structures with difference grain size distributions, diameters and tips of the ZnO nanoneedles or nanorods. In the photoluminescence spectrum, we can observe that, all the samples have a very strong at the wavelengths from 475 to 650 nm, corresponding to relatively broad visible emission peak attributed to the oxygen defects. The experimental results of the sample prepared by ZnSO4exhibit the highest visible luminescent performance. In the infrared absorption spectrum, the band of all the ZnO powders was located at about 500 cm-1, which was the characteristic absorption peak of Zn-O bond. The stretching vibration peak of C=O can be observed at about 1700 cm-1. Meanwhile, there is a strong absorption of the hydroxyl groups in/on Zn (OH)2at around 3450 cm-1, which were from the water molecules.

Plasmonic nanolaser as a new type of ultra-small laser, has gain wide interests due to its breaking diffraction limit of light and fast carrier dynamics characters. Normally, the main problem that need to be solved for plasmonic nanolaser is high loss induced by optical and ohmic losses, which leads to the low quality factor. In this work, InGaN/GaN nanoplate plasmonic nanolaser with large interface area were designed and fabricated, where the overlap between SPs and excitons can be enhanced. The lasing threshold is calculated to be ~6.36 kW/cm2, where the full width at half maximum (FWHM) drops from 27 to 4 nm. And the fast decay time at 502 nm (sharp peak of stimulated lasing) is estimated to be 0.42 ns. Enhanced lasing characters are mainly attributed to the strong confinement of electromagnetic wave in the low refractive index material, which improve the near field coupling between SPs and excitons. Such plasmonic laser should be useful in data storage applications, biological application, light communication, especially for optoelectronic devices integrated into a system on a chip.

Microwave plasma chemical vapor deposition (MPCVD) has been developed as a popular method to grow artificial single crystal diamonds with high crystal quality due to its feasibility and economical effectivity. However, the surface roughness and defects will lead to the generation of cracks in the growth process and significant degradation of the crystal quality of epitaxial CVD diamond. Although optimized growth parameters and subsequent chemico-mechanical polishing (CMP) could improve the surface morphology of CVD diamond layer for device fabrication, more investigations need to be done. In this study, nano-sized patterns were prepared by self-assembled Ni mask and inductively coupled plasma (ICP) etching method on diamond seed, and the height of nanorods were optimized for high quality single crystal diamond growth. According to the Microscope imaging, Raman spectroscopy, photoluminescence (PL) mapping and X-ray diffraction measurements, the influence of diamond nucleation on nanorod structures has been evaluated. The results demonstrate that the surface morphology and crystal quality of CVD diamond layer can be improved by the nano-sized patterned diamond seed, indicating a promising method for diamond-based device fabrication.

X-ray diffraction (XRD) reciprocal space mappings (RSMs) and transmission electron microscopy (TEM) were applied to structurally characterize InGaN multi-quantum-well (MQW) alloys with a novel structure which were epi-grown successively on a rough thick n-InGaN layer with {1 0 1 ¯ m} (2 1 ¯ m〉 modulation direction, was observed by TEM and unconventional shift of satellite peaks in reciprocal space took place in XRD (1 0 1 ¯ 5) RSM. The two scarce phenomena are attributed to the special morphology of V-MQWs.

Incubation and shape transition are considered as two essential processes for nucleating of self-assembly InGaN nanocolumns (NCs) in traditional way. We propose a new approach for nuclei forming directly by in-situ annealing and ion irradiating the InGaN template during growing process. The nanoislands, considered as the nuclei of NCs, were formed by a combinational effect of thermal and ion etching (TIE), which made the gaps of the V-pits deeper and wider. On account of the decomposition of InGaN during TIE process, more nitride-rich amorphous alloys would intent to accumulate in the corroded V-pits. The amorphous alloys played a key role to promote the following growth from 2D regime into Volmer-Weber growth regime so that the NC morphology took place, rather than a compact film. As growth continued, the subsequently epitaxial InGaN alloys on the annealed NC nuclei were suffered in biaxial compressive stress for losing part of indium content from the NC nuclei during the TIE process. Strain relaxation, accompanied by thread dislocations, came up and made the lattice planes misoriented, which prevented the NCs from coalescence into a compact film at later period of growing.

The behaviors of the precipitation and decomposition of carbides in AISI M2 high-speed steel modified by nitrogen and mischmetal were investigated using DSC, XRD, SEM and TEM. The as-cast microstructure of the experimental steel consists of dendrites of iron matrix, networks of eutectic carbides and secondary carbides. The average distance between networks is about 34 μm. The carbides mainly include M2C, M(C,N) and M6C, and their relative contents are 58.5%, 30.3% and 11.2%, respectively. The average spacing between the M2C fibers is 1.5 μm. The decomposition of M2C occurs from 897.2 to 1221.5 °C (heating rate of 200 °C/h). Some precipitated carbide particles occur in the M2C matrix after holding for 15 min at 1100 °C. With increasing holding time, the carbide fibers neck down more and more obviously until they are broken down. The spectral peaks of M2C almost disappear after holding for 60 min. The spectral peaks of M6C gradually strengthen with the holding time, and the relative content of M6C increases to 79.8% after holding for 60 min. After holding for 180 min, the carbide fibers disappear, and the decomposition products consist of fine carbide particles (about 300 nm) and short rod-like carbides (about 3.5 μm).

Multihole ZnO hierarchical architectures were prepared by tartaric acid assisted hydrothermal synthesis, TA acts as a capping agent and structure-directing agent during the synthesis. Hydrazine acts as alkali source. XRD confirmed that that all ZnO possess the hexagonal wurtzite structure, and the crystalline of the sample turns better after annealed. The PL spectra can be tuned by changing TA concentration. The FTIR spectra of ZnO nanostructures shows the main absorbance peaks of all samples are located at about 547 cm−1, which are attributed to the vibrations of elongation of ZnO without any other bonds.

III-Nitride semiconductor materials are considered as promising candidates for photoelectrodes (PEs) due to their adjustable direct band gap covering a very broad spectral range. In this study, InGaN/GaN based p–i–n photoelectrodes have been fabricated and nano-sized surface roughening process has been applied. The photocurrent gets 2.5 times enhancement and the incident photon conversion efficiency (IPCE) is improved to be ∼30% at the wavelength of 400 nm. In addition, the turn-on voltages of InGaN/GaN-based PEs have been effectively reduced from +0.8 V down to about −0.4 V (vs. reversible hydrogen potential, RHE). Such improvements are mainly attributed to reduced dislocation density, increased surface area, and optimized build-in electrical field. These findings give innovative insight to improve photoelectrochemical devices for hydrogen generation.

InGaN/GaN single nanorod (NR) light-emitting diodes (LEDs) have successfully been fabricated by nanoimprint lithography and focused ion beam-induced deposition. The current–voltage characteristics of single NR LEDs show low leakage current of $2\times 10^{\mathrm {-12}}$ A at a reverse bias of −5 V and turn-ON voltage of $\sim 3.8$ V. Linear polarization-oriented parallel to the $c$ -axis with a degree of $\sim 50$ % was discovered from the electroluminescence emission of single NR LEDs.

The mechanisms of reverse leakage in InGaN/GaN multiple-quantum-wells (MQWs) blue and green light-emitting diodes (LEDs) were studied through analyzing the current–voltage ( I–V ) characteristics with the temperature ranging from 50 to 350 K. When the reverse bias V is below 12 V, the leakage current is dominated by the variable-range hopping conduction $(T\rm{ and Poole–Frenkel emission $(T\rm{ > 250\,K)}$ , respectively. As the reverse bias increases $(\vert V\vert \rm{ > 12\,V)}$ , the space-charge-limited conduction mechanism is responsible for the leakage current. It is found that the leakage current is highly associated with the defects density, as well as the trapping capacity of deep level centers; therefore, the lower leakage current of blue LED is mainly attributed to higher thermal activation energy $E_{a}$ due to less deep level centers within GaN/InGaN MQWs structures.

Hybrid white micro-pillar structure light emitting diodes (LEDs) have been manufacture utilizing blue micro-LEDs arrays integrated with 580 nm CIS ((CuInS2-ZnS)/ZnS) core/shell quantum dots. The fabricated hybrid white micro-LEDs have good electrical properties, which are manifested in relatively low turn-on voltage and reverse leakage current. High-quality hybrid white light emission has been demonstrated by the hybrid white micro-LEDs after a systemic optimization, in which the corresponding color coordinates are calculated to be (0.3303, 0.3501) and the calculated color temperature is 5596 K. This result indicates an effective way to achieve high-performance white LEDs and shows great promise in a large range of applications in the future including micro-displays, bioinstrumentation and visible light communication.

Plasmonic nanolasers based on wide bandgap semiconductors are presently attracting immense research interests due to the breaking in light diffraction limit and subwavelength mode operation with fast dynamics. However, these plasmonic nanolasers have so far been mostly realized in the visible light ranges, or most are still under optical excitation pumping. In this work, III-nitride-based plasmonic nanolasers emitting from the green to the deep-ultraviolet (UV) region by energetic electron beam injection are reported, and a threshold as low as 8 kW cm-2 is achieved. A fast decay time as short as 123 ps is collected, indicating a strong coupling between excitons and surface plasmon. Both the spatial and temporal coherences are observed, which provide a solid evidence for exciton-plasmon coupled polariton lasing. Consequently, the achievements in III-nitride-based plasmonic nanolaser devices represent a significant step toward practical applications for biological technology, computing systems, and on-chip optical communication.

Textured materials usually promise an enhanced physical effect along their preferred orientation. However, how to orientate the material, especially from a fissile alloy, is still a great challenge. The transition-metal-based alloy, MnCoSi, is a potential low-cost magnetostrictive material, which application is limited by the poor mechanical property and reduced magnetostriction in polycrystal. Here, we demonstrate that, through the approach of high magnetic field solidification with a slow cooling rate, some textured and dense MnCoSi1−x alloys are obtained, which exhibit giant magnetostriction and enhanced manufacturing performance. Meanwhile, by introducing vacancies of Si element, the metamagnetic transition of MnCoSi alloy is adjusted, giving rise to the room-temperature and reversible magnetostriction under reduced driving magnetic field, which is of significance for the practical applications.

The correlation between surface structural and luminescence properties of InGaN epi-layers grown by metal organic chemical vapour deposition has been investigated. Ring-shaped regions with high In-content are observed around V-pits by spatial resolved cathodoluminescence and energy dispersive X-ray spectroscopy. These ring-shaped regions are found to form a potential energy well with depth about 300 meV with respect to the ordinary regions, which can attract carriers and suppress non-radiative recombination. The causes of the formation of high-In-content region are discussed. This localised characteristic of carriers is supported further by power and temperature dependent photoluminescence results. The understanding of the spatially emission characteristics might be helpful to improving the internal quantum efficiency of InGaN/GaN light emitting diodes (LEDs).

The AlGaN-based deep ultraviolet light-emitting diodes (UV LEDs) with specific design of staggered AlGaN quantum wells are investigated numerically. The proposed UV LEDs with Al 0.45 Ga 0.55 N–Al 0.5 Ga 0.5 N–Al 0.45 Ga 0.55 N and Al 0.5 Ga 0.5 N–Al 0.45 Ga 0.55 N–Al 0.5 Ga 0.5 N staggered quantum well layers exhibit significant improvement for the light output power and carrier injection efficiency compared with the conventional AlGaN UV LED. The enhanced performance of the designed LEDs is explained by the simulated distribution of carrier concentration, radiative recombination rate and wave function overlap in the quantum wells.

Microstructured ZnO have been synthesized by a simple hydrothermal approach, using ZnCl2as the zinc source and N2H4·H2O as the amine precursor in water-ethylene glycol solution at 120 °C for 8 h. The X-ray diffractrometer pattern indicates the pure phase formation of ZnO. Scanning electron microscope images show that the aspect ratio of the ZnO microrod increases by the amount of N2H4·H2O ranging from 0.5 to 1mL, but continuing to 3ml, the aspect ratio of the ZnO microrods decreases. Moreover, the optical band gaps calculated through UV spectroscopy are found to increase from 2.94 (±0.02) to 3.0 (±0.02) eV for samples synthesized at different amounts of hydrazine hydrate ranging from 0.5 to 1mL, respectively.

ZnS thin films were deposited at three different radios of V(NH3·H2O)/V(N2H4) on glass substrates by chemical bath deposition (CBD) method without stirring the deposition bath during the deposition process. The structural and optical properties were analyzed by X-ray diffraction (XRD) and UV-VIS spectrophotometer. The results showed that ZnS thin film deposited at the radio of V(NH3·H2O)/V(N2H4)=15:15 is higher than that of the other two different solutions. With the radio of V(NH3·H2O)/V(N2H4) decreasing from 15:5 to 15:15, homogenous precipitation of Zn (OH)2easily forms in the bath, but ZnS precipitation first become suppressed and then easily forms in solution. It means that the concentration of OH-ion increases with the volume of N2H4increasing, which accelerates the formation of Zn (OH)2. However, when the volume of N2H4increases to 15mL, relatively high concentration of OH-ion not only accelerates the formation of Zn (OH)2, but also be used to the hydrolysis of thiourea. The average transmissions of all the ZnS films from three different solutions (V(NH3·H2O)/V(N2H4)=15:5, 15:10 and 15:15) are greater than 90% for wavelength values in visible region. The direct band gaps range from 3.80 to 4.0eV. The ZnS film deposited for 2.5h with the radio of V(NH3·H2O)/V(N2H4)=15:15 has the cubic structure only after single deposition.

Thin film solar cells (TFSC) are the most potential for development of new and renewable clean energy. The large-scale production and application of TFSC can ease the energy crisis and protect the environment for human. However, buffer layer is a critical layer, which determines the performance of TFSC. This paper reviews the preparation, mechanisms, deposition systems, and development of ZnS thin-film buffer layers and points out that CBD-ZnS thin film is the best buffer layer material taking place of CdS.

ZnS films have been deposited on glass by chemical bath deposition (CBD). The optical and structural properties were analyzed by UV-VIS spectrophotometer and X-ray diffraction (XRD). The results showed that different sides of glass substrate have different thicknesses of the ZnS thin films, which can affect the optical and structural properties of ZnS thin films. The ZnS films of the side of glass substrates back to the solution center are thicker than that of the other side, and the ZnS films from ZnSO4 are thicker than that from Zn (NO3)2. The transmittances lower with the thicknesses of ZnS films increasing. The band gaps exhibit blue response with the thicknesses of ZnS films increasing. From the sides of glass substrates back to the solution center, the (111) reflection of the sphalerite structure can be observed at about 2θ=29.1°, while from the other side toward the solution center showed no significant peak.

As one of the important parameters of dynamic soft reduction technology, reduction position seriously affects the using effect of this technology to decrease center segregation and porosity of continuous casting slabs. According to the actual production conditions, a two-dimensional solidification and heat transfer model was established. In order to obtain more accurate model, the heat transfer coefficient was amending by the pin shooting technique in measuring shell thickness. The laws of the effect of casting speed, superheat degree and specific water flow on reduction position were analyzed respectively and reduction positions were predicted in different working conditions based on the model. The experimental results show that the center segregation and porosity decreased obviously when it produces at the reduction position predicted by the model.

In the last two decades, remarkable progress has been achieved in the field of optoelectronic devices based on III-nitride semiconductors. In terms of photonics applications in the visible-UV spectral range, III-nitrides are one of the most promising materials. For instance, emerging gallium nitride (GaN)-based micro-light-emitting diode (LED) technology for high-resolution display, and UV photo-detection for environmental monitoring, health, and medical applications. In this work, hybrid micro/nano-LEDs with integration of II-VI quantum dots by means of lithography and nano-imprinting patterning techniques are demonstrated, and high-performance red/green/blue and white emissions are achieved. Consequently, plasmonic nanolasers are designed and fabricated using a metal-oxide-semiconductor structure, where strong surface plasmon polariton coupling leads to the efficient lasing with a low excitation threshold from the visible to UV tunable spectral range. Furthermore, performance-improved AlGaN UV solar-blind avalanche photodiodes (APDs) with a separate absorption and multiplication structure by polarization engineering are reported. These APDs deliver a record-high avalanche gain of up to 1.6 × 105 . These newest advances in nano/micro-LEDs, nanolasers, and APDs can shed light on the emerging capabilities of III-nitride in cutting-edge applications.

GaN-based micro light emitting diodes (micro-LEDs) on silicon (Si) substrates with 40 μm in diameter are developed utilizing standard photolithography and inductively coupled plasma etching techniques. From current-voltage curves, the relatively low turn-on voltage of 2.8 V and low reverse leakage current in the order of 10 −8 A/cm 2 indicate good electrical characteristics. As the injection current increases, the electroluminescence emission wavelength hardly shifts at around 433 nm, and the relative external quantum efficiency slightly decays, because the impact of quantum-confined Stark effect is not serious in violet-blue micro-LEDs. Since GaN-LEDs are cost effective on large-area Si and suitable for substrate transfer or vertical device structures, the fabricated micro-LEDs on Si should have promising applications in the fields of high-resolution display and optical communication.

CrN coatings have been deposited successfully by Closed Filed Unbalanced Magnetron Sputter Ion Plating (CFUMSIP). The effect of substrate temperature (TS) and bias voltage (VB) together on microstructure, morphologies and mechanical properties of CrN coatings were studied. The results showed that the deposition rate of CrN coatings declines with the increase of VB Under both room temperature (R.M.) and 300°C. The FCC-CrN disappeared gradually and orth-CrN arised with the increase of VB, and the TS promoted the transformation from FCC - CrN to orth - CrN. The surface morphology of CrN coatings with changed VBs was greatly different, and VB could further improve the mechanical properties of coatings. In this paper, the CrN coating with the parameters (TS =300°C, VB =-30V) had relatively high deposition rate and mechanical properties.

CrN coatings were prepared by Closed Filed Unbalanced Magnetron Sputter Ion Plating (CFUMSIP). The microstructure and morphologies of CrN coatings before and after oxidation were analyzed by XRD and SEM. At the same time, the mechanical properties and oxidation resistance of CrN coating were also studied. The results indicate that the phase in the dense CrN coatings with a hardness of 1979 HV and a adhension of 54 N was the coexistence of Cr, Cr2N and CrN. Besides, The CrN coatings showed good high-temperature oxidation resistance at 700°C while the coating failed at 800°C.

CrAlN coatings have been deposited on K38G alloy by Closed Filed Unbalanced Magnetron Sputter Ion Plating (CFUMSIP). The microstructure, surface and section morphology of CrAlN coatings before and after oxidation were analyzed by XRD and SEM. At the same time, the mechanical properties and oxidation resistance of CrAlN coating were also studied. The results indicate that the phases in the isometric crystal CrAlN coatings with a hardness of 3500 HV and a adhension of 20 N was the coexistence of CrN and AlN. Each element of CrAlN coatings still existed at 800 and 900°C, but it demonstrated better high-temperature oxidation resistance because of denser oxide scale at 800°C. Besides, internal oxidation occurred under the two temperatures.

ZnS films have been deposited on glass substrates by chemical bath deposition (CBD). The optical and structural properties were analyzed by UV-VIS spectrophotometer and X-ray diffraction (XRD). The results showed that the prepared thin films from the solution using N2H4 as second complexing agent were thicker than those from the solution without adding N2H4 in; this is due to using second complexing agent of N2H4, the deposition mechanisms change which is conductive to heterogeneous deposition. When using N2H4 as second complexing agent, the crystallinity of ZnS thin films improved with a significant peak at 2θ=28.96°which can be assigned to the (111) reflection of the sphalerite structure. The transmittances of the prepared films from the solution adding N2H4 in as second complexing agent were over 85%, compared to those from the solution without N2H4 (over 95%). The band gaps of the ZnS films from the solution using N2H4 as second complexing agent were larger (about 4.0eV) than that from those from the solution without N2H4 (about 3.98eV), which indicated that the prepared ZnS films from the solution adding N2H4 in as second complexing agent were better used as buffer layer of solar cells with adequate optical properties. In short, using N2H4 as second complexing agent, can greatly improve the optical and structural properties of the ZnS thin films.

The ZnO nanorods were prepared at 130 °C, 160 °C and 190 °C for 6 h by hydrothermal method. The structural and optical properties of ZnO nanorods were invesitigated by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). XRD pattern analysis showed that the ZnO nanorods are the hexagonal structure (space group P63 mc). No other crystal phases, such as Zn and Zn (OH)2 were detected. FT-IR study identified the sharp peak that appeared at 573 cm-1 is related with the ZnO stretching mode. Also, SEM images revealed that the diameter of a single ZnO crystal ranges from 100 to 300 nm and the length ranges from 1 to 3 μm.

CrN coatings were fabricated by Closed Filed Unbalanced Magnetron Sputtering (CFUMS). The effect of substrate temperature (TS) on phase components, morphologies and mechanical properties of CrN coatings were studied. The results show that the phase in coatings, which has little to do with TS, was the coexistence of Cr, Cr2N and CrN. The grain shape of the columnar crystal CrN coating was the coexistence of pyramidal and plane topography. The hardness and adhension of CrN coating first increased with the rise of temperature, then decreased when the values of both them were constant ones. It has the highest hardness and bonding strength simultaneously at 300°C.

CrN coatings were deposited by Closed Filed Unbalanced Magnetron Sputtering (CFUMS). The effect of N2 flow rate on composition, phase components, morphologies and mechanical properties of CrN coatings were studied. The results show that the deposition rate of CrN coatings declined with the increase of nitrogen flow percentage in a Ar/N2 mixture atmosphere. When the nitrogen flow percentage reached 50% or more, the Cr and N atomic ratio of CrN coatings is close to 1:1. The phase in coatings was the coexistence of Cr, Cr2N and CrN, but the crystal preferred orientation changed significantly with the different N2 flow rates. The columnar crystal CrN coating with low N2 flow rate was denser. The hardness and adhension of CrN coatings have no direct relationship with N2 flow rate.

CrTiAlN hard coatings have been deposited on H13 steel for improving the oxidation resistance by Closed Field Unbalanced Magnetron Sputter Ion Plating (CFUMSIP). The phase components, surface and section morphology of H13 steel before and after oxidation were analyzed by XRD and SEM. The results showed that the columnar crystal film possesses three major parts, i.e., the internal Cr bonding layer, the intermediate CrN transition layer, the external CrTiAlN gradient coating. The selective oxidation of Cr element was found on the surface of uncoated H13 steel while oxidation, but a continuous protective layer was not formed because of low Cr content, finally a lot of alpha Fe2O3 particles took place on the surface of H13 steel owing to the oxidation of the matrix element. O element can diffuse much more easily through the coating and oxide scales at 800 °C, and spallation and cracks were not found during the oxidation. These results indicated that the CrTiAlN coating have excellent high-temperature oxidation resistance at 800 °C.

In this paper, a kind of label-free immunosensor for rapid detection of carcinoembryonic antigen (CEA) based on Pd-Ir bimetallic nanoparticles as a catalyst was prepared. CEA antibody (anti-CEA) was immobilized onto the surface of glassy carbon electrode through the adsorption effect of Pd-Ir bimetallic nanoparticles modified on the electrode using chitosan. When CEA antibody combines with CEA antigen, the formed immunocomplexs blocks the catalytic activity of Pd-Ir bimetal nanoparticles to the reduction of H2O2, leading to decrease in the current response signal. The decrease of the current response of the immunosensor has a linear relationship with the concentration of CEA ranging from 0.05 ng/mL to 50 ng/mL with a detection limit of 0.017 ng/mL at 3σ. The sensor provides a new simple method for the determination of CEA.

The photoelectrodes based on III-nitride semiconductors with high energy conversion efficiency especially for those self-driven ones are greatly desirable for hydrogen generation. In this study, highly ordered InGaN/GaN multiple-quantum-well nanorod-based photoelectrodes have been fabricated by a soft UV-curing nano-imprint lithography and a top-down etching technique, which improve the incident photon conversion efficiency (IPCE) from 16% (planar structure) to 42% (@ wavelength = 400 nm). More significantly, the turn-on voltage is reduced low to −0.6 V, which indicates the possibility of achieving self-driven. Furthermore, SiO2/Si3N4 dielectric distributed Bragg reflectors are employed to further improve the IPCE up to 60%. And the photocurrent (@ 1.1 V) is enhanced from 0.37 mA/cm2 (original planar structure) to 1.5 mA/cm2. These improvements may accelerate the possible applications for hydrogen generation with high energy-efficiency.

Two types of lipases were employed to control the stickies troubles of recycled fiber pulping wastewater in this article. The conditions of enzymatic treatments were optimized and FTIR and GC-MS were used to characterize the changes between the initial and treated wastewater. The optimized conditions of Resinase(R) were: 20u/100mL, 50°C, pH 6.5 ,2h; and those of Lipase(S) were: 15u/100mL, 50°C, pH 9.0 and 2h. Results confirmed that under these optimal conditions of each lipase, both of the two lipases show the excellent performance in the treatment of the stickies of wastewater.

A series of highly ordered c-plane InGaN/GaN elliptic nanorod (NR) arrays were fabricated by our developed soft UV-curing nanoimprint lithography on a wafer. The photoluminescence (PL) integral intensities of NR samples show a remarkable enhancement by a factor of up to two orders of magnitude compared with their corresponding as-grown samples at room temperature. The radiative recombination in NR samples is found to be greatly enhanced due to not only the suppressed non-radiative recombination but also the strain relaxation and optical waveguide effects. It is demonstrated that elliptic NR arrays improve the light extraction greatly and have polarized emission, both of which possibly result from the broken structure symmetry. Green NR light-emitting diodes have been finally realized, with good current-voltage performance and uniform luminescence.

SiO2 coatings were deposited on silver foils substrate by sol–gel method and their atomic oxygen (AO) erosion resistance was tested in a ground-based AO simulator. The surface morphologies and structures of the SiO2 coatings were investigated by Scanning Electron Microscopy (SEM) 、X-Ray Photoelectron Spectroscopy (XPS). The experimental results clearly demonstrate that this kind of coatings provided a good protection from AO attack. The erosion yield of the coatings was 2×10-26 cm3/atom, decreased by 30 times compared with that of the uncoated silver foils. This SiO2 layer significantly retarded the penetration of oxygen atoms, preventing further oxidation of the bulk silver. It was found that after AO exposure, the film structure tends to transfer from SiOH to amorphous SiO2. This implies that a more stable amorphous SiO2 structure could be formed in sol-gel SiO2 film during AO exposure. The results demonstrate that the coatings prepared by sol-gel technique can protect the silver from atomic oxygen erosion and can be used easily for practical application.

A novel polyimide (PI) hybrid nanocomposite containing polyhedral oligomeric silsesquioxane (POSS) had been prepared by copolymerization of octa(aminophenyl)silsesquioxane (OAP-POSS), 4,4’ -oxydianiline (ODA), and pyromellitic dianhydride (PMDA). The AO resistance of these POSS/PI hybrid films was tested in the ground-based AO simulation facility. Exposed and unexposed surfaces have been characterized by X-ray photoelectron spectroscopy and FTIR. The XPS data indicate that the carbon content of the near-surface region is decreased from 63.6 to 19.3 at% after AO exposure. The oxygen and silicon concentrations in the near-surface region increase after AO exposure. The data reveal the formation of a passive inorganic SiO2 layer on the POSS/PI hybrid films during the AO exposure, which serves as a protective barrier preventing further degradation of the underlying polymer with increased exposure to the AO flux. SEM images showed that the surface of the 10 wt% POSS/PI became much less rough than that of the pristine polyimide. The AO resistance of the POSS/PI hybrid films is up to several tenfold than that of the pristine polyimide.

To improve the AO erosion resistance of siloxane coating, the Si ion implantation with nominal dosage of 7×1016 ions/cm2 in siloxane coatings on the polyimide substrate was carried out by using the plasma immersion ion implanter. The Si implanted siloxane coatings before and after AO exposure in the ground-based AO simulation facility were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS). The results of mass measurement shown that, in initial stage of AO exposure the implanted sample had a small mass change, and then was stabilized. The erosion yield of the implanted siloxane coating decreased by a factor of more than two orders of magnitude compared with that of the polyimide film, and decreased by a factor of more than an order of magnitude than that of unimplanted siloxane coatings. The results through SEM and XPS indicated that a continuous high-quality protective SiO2 surface layer was formed on the implanted siloxane coatings after the AO exposure. It can prevent further degradation of the underlying polymer with increased exposure to the AO flux and provide high-quality erosion protection for these materials. The Si implanted materials have a markedly increased erosion resistance than unimplanted siloxane coatings in AO environment.

In order to improve the atomic oxygen (AO) erosion resistance of polyimide films in low earth orbit space environment, a type PDMS/POSS hybrid coating on polyimide substrate was prepared based on a silanol terminated polydimethylsiloxane (PDMS-OH) and Octakis(trimethylsiloxy)octaprismosilsesquioxane (Q8[Si(CH3)3]8) by copolymerizing process in DMAc solution. The atomic oxygen exposure tests were carried out using a ground-based atomic oxygen simulation facility. The mass loss, surface morphology and surface chemical compositions of PDMS/POSS hybrid films before and after exposure to incremental AO flux were investigated by using microbalance and field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS), respectively. The data indicated that a silica-rich layer was formed on the surface of the hybrid coating when the coating is exposed to AO flux, which could provide a protective barrier on the surface preventing further degradation of the polymer during extended exposure to AO and obviously improved the AO resistance of polyimide films.

ZnO films were deposited on nanostructured Al (n-Al) /glass substrate by RF magnetron sputtering. The results shows that the relation (I (002) /I (100) ≈ I annealed (002)/I annealed (100) ≈1.1) shows the rough n-Al surface is suitable for the growth of a-axis orientation. Meanwhile, the influences of substrate roughness, crystallinity and (101) plane of ZnO film deposited on n-Al layer have been discussed. XPS implies more oxygen atoms are bound to Aluminum atoms, which result in the increase of high metallic Zn in the film.