Effect of nano-CaO particle on the microstructure,mechanical properties and corrosion behavior of lean Mg-1Zn alloy

The effects of nano-CaO contents on the microstructure,mechanical properties and corrosion resistance of lean Mg-1Zn alloy were investigated.The results showed that the addition of nano-CaO significantly refined the grain size and improved mechanical properties of the Mg-1Zn alloy.At the same time,CaO reacted with molten Mg in situ to form nano-MgO,whose corrosion product in SBF solution was the same with the degradation product of Mg matrix,resulting in the enhanced compactness of the Mg(OH)_(2) layer and reduced corrosion rate of matrix.The Mg-1Zn alloy had lower corrosion resistance due to excessively large grain size and shedding of corrosion products.The composite with 0.5 wt.%CaO had the best corrosion resistance with a weight loss of 9.875 mg·y^(-1)·mm^(-2)due to the small number of Ca_(2)Mg_(6)Zn_(3) phase and suitable grain size.While for composites with high content of CaO(0.7 wt.%and 1.0 wt.%),they had lower corrosion resistance due to the coexistence of large number of Ca_(2)Mg_(6)Zn_(3) and Mg_(2)Ca at grain boundaries,especially for 1.0 wt.%CaO composite,resulting from the strong micro-galvanic corrosion.

Effects of Annealing Temperature on Structural and Optical Properties of ZnO Thin Films

退火的效果大音阶的第五音胶化纺纱涂层在 Si (100 ) 底层上种的 ZnO 电影的结构、光的性质上的温度被调查。结构、光的性质被 X 光衍射描绘，扫描电子显微镜学和光致发光系列。X 光检查衍射分析证明 ZnO 电影的水晶质量在在高温度退火以后变得更好。谷物尺寸增加，温度增加。在 ZnO 电影的飞机的张力的压力首先增加然后减少，退火的温度增加，这被发现，到达在 700 牴扩瑵摥琠? 桴 ? 楤晦牥湥散椠 ? 湩牴湩楳? 牰灯牥楴獥漠 ? 桴 ? 睴? ?獢牴瑡獥的 1.8 GPa 的最大的价值。

Performance and Stability of Polymer Solar Cells Based on the Blends of Poly(3-Hexylthiophene) and Indene-C_(60) Bis-Adduct

The performance and morphology stability of polymer bulk heterojunetion solar cells based on poly（3-hexylthiophene） （P3HT） as the donor and indene-C6o bisadduct （ICBA） or methanofullerene [6,6]-phenyl C61-butyric acid methyl ester （PCBM） as the aeceptor are compared. Effect of the different donor and aeeeptor weight ratios on photo- voltaic performance of the P3HT：ICBA device is studied. The optimal device achieved power conversion emeiency of 5.51~o with dso of l0.86mA/cm2, Voc of 0.83 V, and fill factor （FF） of 61.1 % under AM 1.5G （lOOmW/cm2） simulated solar illumination. However, the stability measurement shows that cells based on P3HT：ICBA are less stable than those of the device based on P3HT：PCBM. Atomic force microscope results reveal that the morphol- ogy of the P3HT：ICBA film changed considerably during the storage periods due to unstable interpenetrating D-A network. This observation can be explained by the fact that there is lack of intermolecular hydrogen bonds in the P3HT：ICBA system. However, in the P3HT：PCBM system the molecules in the blend film are firmly held together in the solid state by means of intermoleeular hydrogen bonds originating from C-H. ~. Os bonds （where Os comes from the singly-bonded 0 atom of PCBM）, forming a stable three-dimensional network. The measured PL decay lifetimes for P3HT：PCBM and P3HT：ICBA systems are 33.66 ns and 35.34 ns, respectively, indicating that the P3HT：ICBA system has a less efficient exciton separation eftleiency than that of P3HT：PCBM, which may result in the interracial photogenerated charges accumulated on the D： A interface. Such progressive phase segregation between P3HT and ICBA eventually leads to the degradation in performance and deteriorates the stability of the device. We also present an approach to enhance the stability of P3HT：ICBA systems by adding PCBM as the second acceptor. Our results show that by carefully tuning the contents of PCBM as the second acceptor, more stable polymer solar cells can be obtained.

Structural and Magnetic Properties of Fe-Doped Anatase TiO2 Films Annealed in Vacuum

Structural and magnetic properties of Fe-doped anatase TiO2 films fabricated by sol-gel spin coating are investigated. X-ray diffraction measurements reveal that Fe^3＋ ions are incorporated into the TiO2 lattice. No ferromagnetism-related secondary phases and magnetic nanopaxticles are observed in the films. The presence of electron paramagnetic resonance signals at 9- 2.0 supports oxygen vacancies and/or defects generated in the films after annealing in vacuum. Magnetic measurements indicate that Fe-doped anatase TiO2 films are ferromagnetic at room temperature. These observations suggest that oxygen vacancies and/or defects axe energetically favorable for the long range Fe^3＋-Fe^3＋ ferromagnetic coupling in Fe-doped anatase TiO2 films.

Temperature- and Frequency-Dependent Dielectric Properties of La1.5Sr0.5NiO4-δ

We report the temperature-dependent resistivity and dielectric function （1 kHz- 3 MHz） of a charge ordering system La1.5Sr0.5NiO4-δ. The primary data of ac impedance was measured by a four-terminal pair arrangement. Above 180K, the resistivity is independent of frequency. At lower temperatures, the dielectric function couM not be fitted by a Debye model with a single relaxation time, it should have a distribution. At T = 130 K, there is a sudden increase in the p - T relation, meanwhile an anomaly dielectric response occurs on the temperature dependant dielectric spectrum in the whole measured frequency range, in which the dielectric constant has a high value even at high frequency region. Our analysis suggests that the current system would be more consistent with the Zener polaron model.

Fabrication and Characterization of C60-Based Organic Schottky Diodes

We have fabricated organic Schottky barrier diodes with Cu/LiF/C60/Al andwiched construction. Cu and Al are selected as the cathode and the anode, respectively. C60 is used as the organic layer and LiF as the buffer layer inserted between the cathode and C60. After the annealing process, Schottky contact is well formed at the Al/C60 interface and Ohmic contact is formed at the （Cu/LiF）/C60 interface. The current density-voltage （J-V） measurements of the diodes present nonlinear behavior. As a result, the rectification ratio reaches 1×03. The characteristics of the diodes have been analyzed using the energy band diagram. The values of Schottky barrier height ΦB, ideality factor n and reverse saturation current density Js are extracted according to the standard thermionic emission model.

Improved Performance of Phthalocyanine Derivative Field-Effect Transistors by Inserting a Para-Quarterphenyl as the Inducing Layer

我们调查酞毒衍生物用新奇帕拉的器官的地效果晶体管(OFET )- quaterphenyl (p-4p ) 作为导致的层。没有导致层， p 类型(铜酞毒) 的表演和 n 类型(氟化的铜酞毒) 的 p-4p，比作设备有 p-4p 的优化厚度的 OFET 变瘦电影极大地被提高。地效果活动性和二类型的设备的开／关比率被一个数量级控制设备与那些相比改进。这显著改进被归因于 p-4p 的介绍，它能与分子的栈方向平行形成一部高度面向、连续的酞毒衍生物电影到底层。

Lithium Storage Property of Graphite/AlCuFe Quasicrystal Composites

Quasicrystals have long-range quasi-periodic translational ordering and non-crystallographic rotational symmetry.Al-Cu-Fe quasicrystals have great potential for lithium storage because of their high Al content and a large number of defects in the structure.In our previous study(J.Alloys Compd.805(2019)942)we showed that Al-Cu-Fe quasicrystals have good initial capacity whereas its cycle stability is poor.In the present study,graphite/AlCuFe is prepared by the mechanical alloying method.The results show that graphite/AlCuFe quasicrystal composites are successfully synthesized by planetary ball milling at 550 rpm for 80 h.The quasicrystal particle size decreases and the amorphous graphite forms onion-like carbon(OLC)when the two phases mix evenly.OLC forms on the surface of the Al-Cu-Fe quasicrystalline powder.Charge and discharge tests show that graphite/AlCuFe quasicrystal composites have high-stability capacity of 480 mAh/g after 20 cycles,which is larger than the sum of capacities of graphite and Al-Cu-Fe quasicrystals.

Infrared Luminescent Properties of a Pr-Doped KBr Submicron Rod

KBr:Pr with a submicron rod structure is successfully synthesized by a solid-state reaction using absolute alcohol as the abrasive.X-ray diffraction,scanning electron microscopy,photoluminescence spectra and fluorescence decay curves are used to characterize the resulting materials.The influences of Pr^(3+)dopant concentration on the luminescence and lifetime are discussed.Furthermore,luminescent measurements show that KBr:Pr has a high emission intensity compared with other Pr-doped matrixes,which is related to the low phonon energy of KBr.The results suggest that the phonon energy of the host is important in determining the luminescent efficiency.

Improved Performance of Pentacene Organic Field-Effect Transistors by Inserting a V_(2)O_(5) Metal Oxide Layer

We fabricate pentacene-based organic field effect transistors(OFETs),inserting a transition metal oxide(V_(2)O_(5))layer between the pentacene and Al source−drain(S/D)electrodes.The performance of the devices with V_(2)O_(5)/Al S/D electrodes is considerably improved compared to the pentacene−based OFET with only Al S/D electrodes.After the 10-nm V2O5 layer modification,the effective field-effect mobility of the devices increases from 2.7×10^(−3) cm^(2)/V⋅s to 8.93×10−1 cm^(2)/V⋅s.Owing to the change of the injection property,the effective threshold voltage(Vth)is changed from−7.5 V to−5 V and the on/off ratio shifts from 102 to 104.Moreover,the dispersion of sub−threshold current in the devices disappears.These performance improvements are ascribed to the low carrier injection barrier and the reduction of contact resistance.It is indicated that V2O5 layer modification is an effective approach to improve pentacene-based OFET performance.

Performance Improvement of Ambipolar Organic Field Effect Transistors by Inserting a MoO_(3) Ultrathin Layer

We fabricate N,N'-ditridecylperylene-3,4,9,10-tetracarboxylic diimide and pentacene heterostructure organic field effect transistors with a MoO_(3) ultrathin layer between Al source-drain electrode and active layer.By inserting the MoO_(3) layer,the injection barrier of hole carriers is lowered and the contact resistance is reduced.Thus,the performance of the device is improved.The device shows typical ambipolar transport characteristics with effective hole mobility of 4.838×10^(-3) cm^(2)/V·s and effective electron mobility of 1.909×10^(-3) cm^(2)/V·s,respectively.This result indicates that using a MoO_(3) ultrathin 1ayer is an effective way to improve the performance of ambipolar organic field effect transistors.

The Observation of Small Polaron Tunnelling in the ab-Plane of K_(0.85)Fe_(1.66)Se_(2.0)

The temperature-dependent conductivity spectrum from 3×10^(2) Hz to 1×10^(8) Hz in the ab-plane of a K0.85Fe1.66Se2.0 single crystal is probed.The dc measurements indicate that the charge transport can be described well by the variable range hopping model.From the ac conductivity spectrum,clear evidence for small polaron tunnelling with an activation energy of about 155 meV in ab-plane is revealed.With decreasing temperature,the real part of the dielectric spectrum shifts towards lower frequencies and also shows a wider distribution of the relaxation time.Below 140 K,the peak position of the dielectric loss spectra begins to deviate from thermal excitation behavior,reflecting the freezing of the phonon which assists the tunnelling.

Influence of Dopant Concentration on Electroluminescent Performance of Organic White-Light-Emitting Device with Double-Emissive-Layered Structure

A novel phosphorescent organic white-light-emitting device （WOLED） with contiguration of ITO/NPB/CBP： TBPe：rubrene/Zn（BTZ）2：Ir（piq）2（acac）/Zn（BTZ）2/Mg：Ag is fabricated successfully, where the phosphorescent dye bis （1-（phenyl）isoquinoline） iridium （Ⅲ） acetylanetonate （Ir（piq）2 （acac）） doped into bis-（2-（2-hydroxyphenyl） benzothiazole）zinc （Zn（BTZ）2） （greenish-blue emitting material with electron transport character） as the red emitting layer, and fluorescent dye 2,5,8,11-tetra-tertbutylperylene （TBPe） and 5,6,11,12-tetraphenyl-naphthacene （rubrene） together doped into 4,4＇-N,N＇-dicarbazole-biphenyl （CBP） （ambipolar conductivity material） as the blue-orange emitting layer, respectively. The two emitting layers are sandwiched between the hole-transport layer N ,N＇-biphenyl-N , N＇-bis （1-naph thyl）-（1,1＇-biphenyl）-4, 4 Cdiamine （NP B） and electron-transport layer （Zn（BTZ）2 ） The optimum device turns on at the driving voltage of 4.5 V. A maximum external quantum efficiency of 1.53%. and brightness 15000 cd/m^2 are presented. The best point of the Commission Internationale de 1＇Eclairage （CIE） coordinates locates at （0.335, 0.338） at about 13 V. Moreover, we also discuss how to achieve the bright pure white light through optimizing the doping concentration of each dye from the viewpoint of energy transfer process.

Dominance of Antinodal Quasiparticles on the Transport Properties of Heavily Overdoped High-Tc Cuprates： Infrared-Reflectance Spectra

The infrared reflectance spectrum up to 2500cm^-1 for heavily overdoped T1-2201 at 300 K has been analysed under the semiclassical approximation. In this approach, we use two independent sets of parameters to fit the reflectance： the momentum-dependent Fermi velocity vk and the momentum-dependent scattering rate τ^-1 （εk ）. Unlike the case at optimal doping in which the transport properties are dominated by the nodal quasi-particles （QPs）, both the lifetime and the Fermi velocity of the QPs in the antinodal region near the Fermi surface increase remarkably for the heavily overdoped samples. Our fitting results indicate that the antinodal QPs tend to dominate the transport properties in heavily overdoped high-Tc cuprates.

Performance of Organic Field Effect Transistors with Self-Improved Cu/Organic Interfaces

We fabricate pentacene-based organic field effect transistors （OFETs） with Cu as source and drain （S-D） electrodes. The fabricated devices stored for ten hours under ambient atmospheric conditions exhibit superior performance compared with the as-prepared devices. The field-effect mobility increases from 0. 012 to 0.03 cm^2 V^-1 s^-1, and the threshold voltage downshifts from -14 to -9 V. The on/off current ratios are close to the order of 10^4. The improved performance of the stored devices is attributed to the formation of thin Cu oxide at the Cu electrodes/organic interfaces. These results suggest a simple and available way to optimize device properties and to reduce fabrication cost for OFETs.

Constructing a 3D multichannel structure to enhance performance of Ni–Co–Mn hydroxide electrodes for flexible supercapacitors

The balancing of the electrochemical performance,mechanical stability,and processing technology for applying supercapacitors to flexible and wearable electronics continues to encounter severe challenges.Herein,we prepare Ni-Co-Mn hydroxide electrodes with a threedimensional multichannel structure via a simple hydrothermal method.These are constructed using vertically contiguous nano sheets with a uniform thickness and rough surface.The electrodes can provide numerous electroactive sites and accelerate the transmission of electrolyte ions.The relationship between the structure and electrochemical performances is verified by experiments and theoretical calculations.Two-dimensional(2D)planar and one-dimensional(1D)fiber electrodes are prepared using a flexible carbon cloth(CC)and carbon fiber(CF),respectively,as substrates.The assembled quasi-solid-state flexible asymmetric supercapacitor(FASC)with a twodimensional sandwich structure using NiCoMn-OH/CC as the electrode achieves a remarkable energy density of73.8 Wh·kg^(-1)at a power density of 1.03 kW·kg^(-1).The quasi-solid-state FASC with a 1D linear structure using NiCoMn-OH/CF as the electrode also attains a high energy density(12.9 Wh·kg^(-1)at a power density of0.75 W·kg^(-1)).Moreover,the electrochemical performances of the NiCoMn/CC//AC/CC and NiCoMn/CF//AC/CF FASCs are not disturbed at different bending angles(0°,45°,90°,135°and 180°),This indicates the superior flexibility of the devices.We also assemble a self-powered energy-harvesting storage system by integrating FASCs and commercial solar cells to verify its practicability.It displays sustainable development potential for energy storage.

Vortex chains induced by anisotropic spin-orbit coupling and magnetic field in spin-2 Bose-Einstein condensates

We investigate the anisotropic spin-orbit coupled spin-2 Bose-Einstein condensates with Ioffe-Pritchard magnetic field.With nonzero magnetic field,anisotropic spin-orbit coupling will introduce several vortices and further generate a vortex chain.Inside the vortex chain,the vortices connect to each other,forming a line along the axis.The physical nature of the vortex chain can be explained by the particle current and the momentum distribution.The vortex number inside the vortex chain can be influenced via varying the magnetic field.Through adjusting the anisotropy of the spin-orbit coupling,the direction of the vortex chain is changed,and the vortex lattice can be triggered.Moreover,accompanied by the variation of the atomic interactions,the density and the momentum distribution of the vortex chain are affected.The realization and the detection of the vortex chain are compatible with current experimental techniques.

Manipulating vortices in F=2 Bose-Einstein condensates through magnetic field and spin-orbit coupling

We investigate the vortex structures excited by Ioffe-Pritchard magnetic field and Dresselhaus-type spin-orbit coupling in F=2 ferromagnetic Bose-Einstein condensates.In the weakly interatomic interacting regime,an external magnetic field can generate a polar-core vortex in which the canonical particle current is zero.With the combined effect of spin-orbit coupling and magnetic field,the ground state experiences a transition from polar-core vortex to Mermin-Ho vortex,in which the canonical particle current is anticlockwise.For fixed spin-orbit coupling strengths,the evolution of phase winding,magnetization,and degree of phase separation with magnetic field are studied.Additionally,with further increasing spin-orbit coupling strength,the condensate exhibits symmetrical density domains separated by radial vortex arrays.Our work paves the way to explore exotic topological excitations in high-spin systems.

Enhanced Performance and Stability in Polymer Photovoltaic Cells Using Ultraviolet-Treated PEDOT:PSS

We investigate the effects of ultraviolet(UV)irradiation treatment with varying irradiation intensities for different treatment times of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)film on the performance and stability of polymer solar cells(PSCs)based on regioregular poly(3-hexylthiophene)(P3HT)and methanofullerene[6,6]-phenyl C61-butyric acid methyl ester(PCBM)blend.Ultraviolet-visible transmission spectra,x-ray photoelectron spectroscopy,contact angle measurement,atomic force microscopy and the Kelvin probe method are conducted to characterize the UV-treated PEDOT:PSS film.The results demonstrate that UV treatment can improve the power conversion efficiency(PCE)and stability of PSCs effectively.The best performance is achieved under 1200μW/cm^(2) UV treatment for 50 min.Compared to the control device,the optimized device exhibits enhanced performance with a V_(oc) of 0.59 V,J_(sc) of 12.3 mA/cm^(2),fill factor of 51%,and PCE of 3.64%,increased by 3.5%,33%,8.7%and 50%,respectively.The stability of the PSCs is enhanced by 2.5 times simply through the UV treatment on the PEDOT:PSS buffer layer.The improvement in the device performance and stability is attributed to the improvement in the wettability property and the increase in the work function of the PEDOT:PSS film by UV treatment,while the impact of UV treatment on the transparency of the PEDOT:PSS film is negligible.The strategy of using UV treatment to improve device performance and stability is attractive due to its simplicity,cost-effectiveness,and because it is suitable for large-scale commercial production.

A Simple Interconnection Layer for Tandem Organic Solar Cells with Improved Efficiency and Fill Factor

We demonstrate a simple interconnection layer （ICL） that can be employed in tandem organic solar cells. An ICL with an optimized structure of Ca/Au/MoO3 is used between two sub cells composed of identical regioregularpoly（3-hexylthiophen） （P3HT）：[6,6]-phenyl C61-butyric acid methylester （PCBM） photoactive layers. Power conversion efficiency （PCE） of 3.24% and fill factor （FF） of 68.0% are achieved with such an ICL under simulated sunlight （1 O0 m W. cm- 2 ）. Compared with the best values of devices with ICLs of Ca/Al/MoOa, PCE is improved by 68.9% and FF is improved by 15.5%. The improved performances are attributed to the optical and electrical balances in both sub cells. The presented ICL extracts free charges efficiently from both sub cells thereby suppressing the exaction recombination in each sub cell.