A novel Co（Ⅱ） coordination polymer was hydrothermally synthesized and characterized. The crystal crystallizes in the monoclinic system, space group C c with a =1.772 59（4） nm, b = 1.150 00（10） nm , c =2.452 76...A novel Co（Ⅱ） coordination polymer was hydrothermally synthesized and characterized. The crystal crystallizes in the monoclinic system, space group C c with a =1.772 59（4） nm, b = 1.150 00（10） nm , c =2.452 76（11） nm, β =92.723（3）°, V =4.994 3 nm 3, Z =4, R =0.080 9, wR =0.213 4. The polymer based on [Co（μ 4,4′ bipy）（4,4′ bipy） 2(（H 2O） 2] n linear chains was cross linked by the H bond bridge of Co—OH 2…4,4′ bipy—Co and π π stacking interaction, producing extended 2D ladder structure. The susceptibility of the polymer at variable temperature（2 0300 K） shows a weak antiferromagnetic interaction and implies that the polymer has the tendency of spin transition. Also, the result of surface photovoltage spectroscopy（SPS） reveals that the polymer has a significant photo electronic transferring property in UV Vis regions, which correspond to π π transition, L M charge transfer transition（shoulder） and d d transition of Co 2+ ion, respectively.展开更多
The fluorine-containing organic polymer was synthesized from 3, 3＇, 4, 4＇-Bisphenyltetracarboxylic （BPDA）, and 2,2-Bis （3-amino-4-hydroxyyphenyl） hexafluoropropane （6FHP）. It is a first-step preparation of a p...The fluorine-containing organic polymer was synthesized from 3, 3＇, 4, 4＇-Bisphenyltetracarboxylic （BPDA）, and 2,2-Bis （3-amino-4-hydroxyyphenyl） hexafluoropropane （6FHP）. It is a first-step preparation of a preimided hydroxy-containing polyimide, followed by the covalent bonding of an active chromophore, dispersed red 19 （DR19）, onto the backbone of the polyimide via the Mitsunobu reaction. The nonlinear optical （NLO） containing polyimide was synthesized. The differential scanning calorimeter （DSC）and thermal gravimetric analysis （TGA） exhibited Tg and the temperature Tg at which 5 % mass losses occurring of polymer were 248 and 309 ℃, respectively. A reflective electro-optic （EO） modulator using this polymer was fabricated. The optical nonlinearities were determined to be d33 = 5. 209×10^-9 esu （poling voltage of 3.6 kV, 205 ℃） and d33 =7. 418×10^-9esu （poling voltage of 3. 8 kV, 210 ℃） by the second harmonic generation method in in-situ condition at a fundamental wavelength of 1 064 nm. The EO coefficients 733 of the polymer layer in the EO modulator were determined to be 2. 182 pm/V （poling voltage of 3.6 kV, 205 ℃） and 3. 107 pm/V （poling voltage of 3.8 kV, 210 ℃） at 1064 nm by an attenuated-total-reflection （ATR） method.展开更多
SnO2 nano particles with various Pd-doping concentrations were prepared using a template-free hydrothermal method.The effects of Pd doping on the crystal structure,morphology,microstructure,thermal stability and surfa...SnO2 nano particles with various Pd-doping concentrations were prepared using a template-free hydrothermal method.The effects of Pd doping on the crystal structure,morphology,microstructure,thermal stability and surface chemistry of these nano particles were characterized by transmission electron microscope,X-ray diffractometer and X-ray photoelectron spectroscope respectively.It was observed that Pd-doping had little effect on the grain sizes of the obtained SnO2 nano particles during the hydrothermal route.During thermal annealing,Pd-doping could restrain the growth of grain sizes below 500℃ while the grain growth was promoted when the temperature increased to above 700℃.XPS results revealed that Pd existed in three chemical states in the as-synthesized sample as Pd^0,Pd^2＋ and Pd^4＋,respectively.Pd^4＋ was the main state which was responsible for improving the gas-sensing property.The optimal Pd-doping concentration for better gas-sensing property and thermal stability was 2.0%-2.5% （mole fraction）.展开更多
Thin transparent oxide conducting films(TCOFs)of titanium and gallium substituted zinc oxide(TGZO)were fabricated via radio frequency(RF)magnetron sputtering technique.The effects of RF power on electrical,linear and ...Thin transparent oxide conducting films(TCOFs)of titanium and gallium substituted zinc oxide(TGZO)were fabricated via radio frequency(RF)magnetron sputtering technique.The effects of RF power on electrical,linear and nonlinear optical characteristics were investigated by Hall tester,Ultraviolet(UV)-visible spectrophotometer and optical characterization method.The results indicate that RF power significantly influences the electrical and optical properties of the deposited films.As RF power raises,the resistivity and Urbach energy fall initially and then rise,while the figure of merit,mean visible transmittance and optical bandgap show the reverse variation trend.At RF power of 190 W,the TGZO sample exhibits the highest electro-optical properties,with the maximum figure of merit(1.14×10^(4)Ω^(-1)∙cm^(-1)),mean visible transmittance(86.9%)and optical bandgap(3.50 eV),the minimum resistivity(6.26×10^(-4)Ω∙cm)and Urbach energy(174.23 meV).In addition,the optical constants of the deposited films were determined by the optical spectrum fitting method,and the RF power dependence of nonlinear optical properties was studied.It is observed that all the thin films exhibit normal dispersion characteristics in the visible region,and the nonlinear optical parameters are greatly affected by the RF power in the ultraviolet region.展开更多
Two organic dyes XSS1 and XS52 derivated from triarylamine and indoline are synthesized for dye-sensitized solar ceils （DSCs） employing cobalt and iodine redox shuttles. The effects of dye structure upon the photoph...Two organic dyes XSS1 and XS52 derivated from triarylamine and indoline are synthesized for dye-sensitized solar ceils （DSCs） employing cobalt and iodine redox shuttles. The effects of dye structure upon the photophysical, electro-chemical characteristics and cell perfor- mance are investigated. XS51 with four hexyloxyl groups on triarylamine performs better steric hindrance and an improvement of photovoltage. X852 provides higher short-circuit photocurrent density due to the strong electron-donating capability of indoline unit. The results from the redox electrolyte on cell performances indicate that the synthesized dyes are more suitable for tris（1,10-phenanthroline）cobalt（II/III） redox couple than I-/I3- redox couple in assembling DSCs. Application of X852 in the cobalt electrolyte yields a DSC with an overall power conversion efficiency of 6.58% under AM 1.5 （100 mW/cm2） irradiation.展开更多
The structural, elastic, electronic and optical properties for U3Si2-type AlSc2Si2 compound under pressure were systematically investigated by using the first-principles calculations. The values of elastic constants a...The structural, elastic, electronic and optical properties for U3Si2-type AlSc2Si2 compound under pressure were systematically investigated by using the first-principles calculations. The values of elastic constants and elastic moduli indicate that AlSc2Si2 keeps mechanical stability under high pressure. The mechanical properties of AISc2Si2 are compared with those of Al3Sc. The results indicate that AlSc2Si2 is harder than AI3Sc. Anisotropic constant AU and 3D curved surface of elastic moduli predict that AISc2Si2 is obviously anisotropic under pressure. The electronic structure of AlSc2Si2 exhibits metallic character and the metallicity decreases with the elevated pressure. In addition, optical properties as a function of pressure were calculated and analyzed. The present work provides theoretical support for further experimental work and industrial applications.展开更多
The Ti−45Nb(wt.%)alloy properties were investigated in relation to its potential biomedical use.Laser surface modification was utilized to improve its performance in biological systems.As a result of the laser treatme...The Ti−45Nb(wt.%)alloy properties were investigated in relation to its potential biomedical use.Laser surface modification was utilized to improve its performance in biological systems.As a result of the laser treatment,(Ti,Nb)O scale was formed and various morphological features appeared on the alloy surface.The electrochemical behavior of Ti−45Nb alloy in simulated body conditions was evaluated and showed that the alloy was highly resistant to corrosion deterioration regardless of additional laser surface modification treatment.Nevertheless,the improved corrosion resistance after laser treatment was evident(the corrosion current density of the alloy before laser irradiation was 2.84×10^(−8)A/cm^(2),while that after laser treatment with 5 mJ was 0.65×10^(−8)A/cm^(2))and ascribed to the rapid formation of a complex and passivating bi-modal surface oxide layer.Alloy cytotoxicity and effects of the Ti−45Nb alloy laser surface modification on the MRC-5 cell viability,morphology,and proliferation were also investigated.The Ti−45Nb alloy showed no cytotoxic effect.Moreover,cells showed improved viability and adherence to the alloy surface after the laser irradiation treatment.The highest average cell viability of 115.37%was attained for the alloy laser-irradiated with 15 mJ.Results showed that the laser surface modification can be successfully utilized to significantly improve alloy performance in a biological environment.展开更多
A series of CH2, NH, O, and Se substituted 2,1,3-benzothiadiazote derivatives have been designed and investigated computationally to elucidate their potential as organic light-emitting materials for organic light-emit...A series of CH2, NH, O, and Se substituted 2,1,3-benzothiadiazote derivatives have been designed and investigated computationally to elucidate their potential as organic light-emitting materials for organic light-emitting diodes. Both ab initio Hartree-Foek and hybrid density functional methods are used. It is found that S by CH2, NH, O, and Se makes it possible transport properties of the pristine molecule adjusting the central aromatic ring by replacing to fine-tune the electronic, optical, and charge展开更多
Ho^3＋-doped titanium dioxide（TiO2：Ho^3＋） downconversion（DC） nanowires were synthesized through a simple hydrothermal method followed by a subsequent calcination process after being immersed in Ho（NO3）3 aqueou...Ho^3＋-doped titanium dioxide（TiO2：Ho^3＋） downconversion（DC） nanowires were synthesized through a simple hydrothermal method followed by a subsequent calcination process after being immersed in Ho（NO3）3 aqueous solution. Moreover, TiO2：Ho^3＋ nanowires（HTNWs） were used as the photoanode in dye-sensitized solar cells（DSSCs） to investigate their photoelectric properties. Scanning electron microscopy（SEM） and X-ray diffraction（XRD） were used to characterize the morphology and structure of the material, respectively. The photofluorescence and ultraviolet-visible absorption spectra of HTNWs reveal a DC from the near and middle ultraviolet light to visible light which matches the strong absorbed region of the N719 dye. Compared with the pure TNW photoanode, HTNWs DC photoanodes show greater photovoltaic efficiency. The photovoltaic conversion efficiency（η） of the DSSCs with HTNWs photoanode doped with 4% Ho2O3（mass fraction） is two times that with pure TNW photoanode. This enhancement could be attributed to HTNWs which could extend the spectral response range of DSSCs to the near and middle ultraviolet region and increase the short-circuit current density（Jsc） of DSSCs, thus leading to the enhancement of photovoltaic conversion efficiency.展开更多
Laser-weldable Sip-SiCp/Al hybrid composites with high volume fraction （60%-65%） of SiC reinforcement were fabricated by compression moulding and vacuum gas pressure infiltration technology. Microscopic observation ...Laser-weldable Sip-SiCp/Al hybrid composites with high volume fraction （60%-65%） of SiC reinforcement were fabricated by compression moulding and vacuum gas pressure infiltration technology. Microscopic observation displayed that the Sip-SiCp/Al hybrid composites with bilayer structure were compact without gas pores and the intergradation between Sip/Al layer and SiCp/Al layer was homogeneous and continuous. Further investigation revealed that the Sip-SiCp/Al hybrid composites possessed low density （2.96 g/cm^3）, high gas tightness （1.0 mPa·cm^3）/s）, excellent thermal management function as a result of high thermal conductivity （194 W/（m·K） and low coefficient of thermal expansion （7.0×10^-6 K-1）. Additionally, Sip-SiCp/Al hybrid composites had outstanding laser welding adaptability, which is significantly important for electronic packaging applications. The gas tightness of components after laser welding （48 mPa·cm^3）/s） can well match the requirement of advanced electronic packaging. Several kinds of these precision components passed tests and were put into production.展开更多
Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, p...Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, photocathodic protection and photoelectrochemical properties of TiO2 thin films were investigated. It is indicated that the photoelectrical performance of the Zn?TiO2 films is enhanced with the addition of Zn element compared with the pure-TiO2 film and the largest decline by 897 mV in the electrode potential is achieved under 300 °C heat treatment. SEM?EDS analyses show that Zn element is unevenly distributed in Zn?TiO2 films; XRD patterns reveal that the grain size of Zn?TiO2 is smaller than that of pure-TiO2; FTIR results indicate that Zn - O bond forms on Zn?TiO2 surface. Ultraviolet visible absorption spectra prove that Zn?TiO2 shifts to visible light region.Mott?Shottky curves show that the flat-band potential of Zn?TiO2 is more negative and charge carrier density is bigger than that ofpure-TiO2, implying that under the synergy of the width of the space-charge layer, carrier density and flat-band potential, Zn?TiO2 with 300 °C heat treatment displays the best photocathodic protection performance.展开更多
From the UV?Vis absorption spectra,the FT-IR absorption spectra and the Raman spectra,it is deduced that Co ionsprimarily occupy the tetrahedral(A)site,with a minor number of them entering into the octahedral(B)site i...From the UV?Vis absorption spectra,the FT-IR absorption spectra and the Raman spectra,it is deduced that Co ionsprimarily occupy the tetrahedral(A)site,with a minor number of them entering into the octahedral(B)site in the Ni1?xCoxCr2O4compounds.The origin of the position disorder of the Co ions is consistent with the similar ionic radii of the Co ion(0.65?)and theCr ion(0.62?)at B site.The FT-IR peak at about510cm?1shifts towards high frequency side with the increasing cobalt content.Itis resulted from the reduction of the cation?oxygen distance in the octahedron by the replacement of the Ni2+with the Co2+ions.Themagnetic measurement shows that Curie temperatures(TC)are75and90K for the compounds with x=0.2and0.8,respectively.展开更多
Er-doped BiVO4 composite photocatalyst was hydrothermal synthesized and characterized by X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray Spectroscopy, X-ray photoelectron spectroscopy, ...Er-doped BiVO4 composite photocatalyst was hydrothermal synthesized and characterized by X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray Spectroscopy, X-ray photoelectron spectroscopy, and UV-Vis diffuse reflectance spectra techniques. The activity of the catalyst was determined by oxidative decomposition of methyl orange in aqueous solution under visible-light irradiation. X-ray photoelectron spectroscopy and energy-dispersive X-ray Spectroscopy analysis revealed that the doped Er existed in the form of Er2O3. It also showed that the Er doping can enhance the visible-light absorption abilities of catalysts and their visible-light-driven photocatalytic activities in comparison with those of pure BiVO4.展开更多
In this study,a high-purity In_(2)Ga_(2)ZnO_(7) ceramic target was used to deposit indium gallium zinc oxide(IGZO)films by RF magnetron sputtering technology.The microstructure,growth state,optical and electrical prop...In this study,a high-purity In_(2)Ga_(2)ZnO_(7) ceramic target was used to deposit indium gallium zinc oxide(IGZO)films by RF magnetron sputtering technology.The microstructure,growth state,optical and electrical properties of the IGZO films were studied.The results showed that the surface of the IGZO film was uniform and smooth at room temperature.As the substrate temperature increased,the surface roughness of the film gradually increased.From room temperature to 300℃,all the films maintained amorphous phase and good thermal stabilities.Moreover,the transmission in the visible region decreased from 91.93%to 91.08%,and the band gap slightly decreased from 3.79 to 3.76 eV.The characterization of the film via atomic force microscope(AFM)and X-ray photoelectron spectroscopy(XPS)demonstrated that the film prepared at room temperature exhibited the lowest surface roughness and the largest content of oxygen vacancies.With the rise in temperature,the non-homogeneous particle distribution,increase in the surface roughness,and reduction in the number of oxygen vacancies resulted in lower performance of theα-IGZO film.Comprehensive analysis showed that the best optical and electrical properties can be obtained by depositing IGZO films at room temperature,which indicates their potential applications in flexible substrates.展开更多
Al-doped ZnO(AZO)thin films were deposited on glass substrates by rf-sputtering at room temperature.The effects of substrate rotation speed(ωS)on the morphological,structural,optical and electrical properties were in...Al-doped ZnO(AZO)thin films were deposited on glass substrates by rf-sputtering at room temperature.The effects of substrate rotation speed(ωS)on the morphological,structural,optical and electrical properties were investigated.SEM transversal images show that the substrate rotation produces dense columnar structures which were found to be better defined under substrate rotation.AFM images show that the surface particles of the samples formed under substrate rotation are smaller and denser than those of a stationary one,leading to smaller grain sizes.XRD results show that all films have hexagonal wurtzite structure and preferred c-axis orientation with a tensile stress along the c-axis.The average optical transmittance was above90%in UV-Vis region.The lowest resistivity value(8.5×10?3Ω·cm)was achieved atωS=0r/min,with a carrier concentration of1.8×1020cm?3,and a Hall mobility of4.19cm2/(V·s).For all other samples,the substrate rotation induced changes in the carrier concentration and Hall mobility which resulted in the increasing of electrical resistivity.These results indicate that the morphology,structure,optical and electrical properties of the AZO thin films are strongly affected by the substrate rotation speed.展开更多
The electro-physical properties of thin layers of rhenium chalcogenides＇ alloys, their dynamical and static ampere-voltaic characteristics were investigated. During the investigation of static and dynamical ampere-vo...The electro-physical properties of thin layers of rhenium chalcogenides＇ alloys, their dynamical and static ampere-voltaic characteristics were investigated. During the investigation of static and dynamical ampere-voltaic characteristics of rectifying contact of aluminium and rhenium chalcogenides＇ alloys the switching effects were found.展开更多
The quality of perovskite layers has a great impact on the performance of perovskite solar cells(PSCs).However,defects and related trap sites are generated inevitably in the solutionprocessed polycrystalline perovskit...The quality of perovskite layers has a great impact on the performance of perovskite solar cells(PSCs).However,defects and related trap sites are generated inevitably in the solutionprocessed polycrystalline perovskite films.It is meaningful to reduce and passivate the defect states by incorporating additive into the perovskite layer to improve perovskite crystallization.Here an environmental friendly 2D nanomaterial protonated graphitic carbon nitride(p-g-C_(3)N_(4))was successfully synthesized and doped into perovskite layer of carbon-based PSCs.The addition of p-g-C_(3)N_(4)into perovskite precursor solution not only adjusts nucleation and growth rate of methylammonium lead tri-iodide(MAPb I3)crystal for obtaining flat perovskite surface with larger grain size,but also reduces intrinsic defects of perovskite layer.It is found that thep-g-C_(3)N_(4) locates at the perovskite core,and the active groups-NH_(2)/NH_(3)and NH have a hydrogen bond strengthening,which effectively passivates electron traps and enhances the crystal quality of perovskite.As a result,a higher power conversion efficiency of 6.61% is achieved,compared with that doped with g-C_(3)N_(4)(5.93%)and undoped one(4.48%).This work demonstrates a simple method to modify the perovskite film by doping new modified additives and develops a low-cost preparation for carbon-based PSCs.展开更多
The thickness of TiO2 film is vital to realize the optimization on photovoltaic performance of dye sensitized solar cells （DSSCs）. Herein, the process of charge separation in DSSCs was simulated by using a drift-dif...The thickness of TiO2 film is vital to realize the optimization on photovoltaic performance of dye sensitized solar cells （DSSCs）. Herein, the process of charge separation in DSSCs was simulated by using a drift-diffusion model. This model allows multiple-trapping diffu- sion of photo-generated electrons, as well as the back reaction with the electron acceptors in electrolyte, to be mimicked in both steady and non-steady states. Numerical results on current-voltage characteristics allow power conversion efficiency to be maximized by varying the thickness of TiO2 film. Charge collection efficiency is shown to decrease with film thick- ness, whereas the flux of electron injection benefits from the film thickening. The output of photocurrent is actually impacted by the two factors. Furthermore, recombination rate constant is found to affect the optimized film thickness remarkably. Thicker TiO2 film is suitable to the DSSCs in which back reaction is suppressed sufficiently. On the contrary, the DSSCs with the redox couple showing fast electron interception require thinner film to alleviate the charge loss via recombination. At open circuit, electron density is found to decrease with film thickness, which engenders not only the reduction of photovoltage but also the increase of electron lifetime.展开更多
文摘A novel Co（Ⅱ） coordination polymer was hydrothermally synthesized and characterized. The crystal crystallizes in the monoclinic system, space group C c with a =1.772 59（4） nm, b = 1.150 00（10） nm , c =2.452 76（11） nm, β =92.723（3）°, V =4.994 3 nm 3, Z =4, R =0.080 9, wR =0.213 4. The polymer based on [Co（μ 4,4′ bipy）（4,4′ bipy） 2(（H 2O） 2] n linear chains was cross linked by the H bond bridge of Co—OH 2…4,4′ bipy—Co and π π stacking interaction, producing extended 2D ladder structure. The susceptibility of the polymer at variable temperature（2 0300 K） shows a weak antiferromagnetic interaction and implies that the polymer has the tendency of spin transition. Also, the result of surface photovoltage spectroscopy（SPS） reveals that the polymer has a significant photo electronic transferring property in UV Vis regions, which correspond to π π transition, L M charge transfer transition（shoulder） and d d transition of Co 2+ ion, respectively.
基金Jiangsu Planned Projects for Postdoctoral ResearchFunds(No0602037B)the Natural Science Foundation of Higher Edu-cation Institutions of Jiangsu Province (No05KJB150016)+1 种基金the Nation-al Natural Science Foundation of China (No50377005)the Fund ofJiangsu University (No06JDG015)
文摘The fluorine-containing organic polymer was synthesized from 3, 3＇, 4, 4＇-Bisphenyltetracarboxylic （BPDA）, and 2,2-Bis （3-amino-4-hydroxyyphenyl） hexafluoropropane （6FHP）. It is a first-step preparation of a preimided hydroxy-containing polyimide, followed by the covalent bonding of an active chromophore, dispersed red 19 （DR19）, onto the backbone of the polyimide via the Mitsunobu reaction. The nonlinear optical （NLO） containing polyimide was synthesized. The differential scanning calorimeter （DSC）and thermal gravimetric analysis （TGA） exhibited Tg and the temperature Tg at which 5 % mass losses occurring of polymer were 248 and 309 ℃, respectively. A reflective electro-optic （EO） modulator using this polymer was fabricated. The optical nonlinearities were determined to be d33 = 5. 209×10^-9 esu （poling voltage of 3.6 kV, 205 ℃） and d33 =7. 418×10^-9esu （poling voltage of 3. 8 kV, 210 ℃） by the second harmonic generation method in in-situ condition at a fundamental wavelength of 1 064 nm. The EO coefficients 733 of the polymer layer in the EO modulator were determined to be 2. 182 pm/V （poling voltage of 3.6 kV, 205 ℃） and 3. 107 pm/V （poling voltage of 3.8 kV, 210 ℃） at 1064 nm by an attenuated-total-reflection （ATR） method.
基金Projects(60806032,20975107) supported by the National Natural Science Foundation of ChinaProject(2009R10064) supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars of Education Ministry,China+2 种基金 Project(2009R10064) supported by "Qianjiang Talent Program"Projects(2009A610058,2009A610030) supported by the Ningbo Natural Science Foundation,ChinaProject supported by K.C.WONG Magna Fund in Ningbo University,China
文摘SnO2 nano particles with various Pd-doping concentrations were prepared using a template-free hydrothermal method.The effects of Pd doping on the crystal structure,morphology,microstructure,thermal stability and surface chemistry of these nano particles were characterized by transmission electron microscope,X-ray diffractometer and X-ray photoelectron spectroscope respectively.It was observed that Pd-doping had little effect on the grain sizes of the obtained SnO2 nano particles during the hydrothermal route.During thermal annealing,Pd-doping could restrain the growth of grain sizes below 500℃ while the grain growth was promoted when the temperature increased to above 700℃.XPS results revealed that Pd existed in three chemical states in the as-synthesized sample as Pd^0,Pd^2＋ and Pd^4＋,respectively.Pd^4＋ was the main state which was responsible for improving the gas-sensing property.The optimal Pd-doping concentration for better gas-sensing property and thermal stability was 2.0%-2.5% （mole fraction）.
文摘Thin transparent oxide conducting films(TCOFs)of titanium and gallium substituted zinc oxide(TGZO)were fabricated via radio frequency(RF)magnetron sputtering technique.The effects of RF power on electrical,linear and nonlinear optical characteristics were investigated by Hall tester,Ultraviolet(UV)-visible spectrophotometer and optical characterization method.The results indicate that RF power significantly influences the electrical and optical properties of the deposited films.As RF power raises,the resistivity and Urbach energy fall initially and then rise,while the figure of merit,mean visible transmittance and optical bandgap show the reverse variation trend.At RF power of 190 W,the TGZO sample exhibits the highest electro-optical properties,with the maximum figure of merit(1.14×10^(4)Ω^(-1)∙cm^(-1)),mean visible transmittance(86.9%)and optical bandgap(3.50 eV),the minimum resistivity(6.26×10^(-4)Ω∙cm)and Urbach energy(174.23 meV).In addition,the optical constants of the deposited films were determined by the optical spectrum fitting method,and the RF power dependence of nonlinear optical properties was studied.It is observed that all the thin films exhibit normal dispersion characteristics in the visible region,and the nonlinear optical parameters are greatly affected by the RF power in the ultraviolet region.
文摘Two organic dyes XSS1 and XS52 derivated from triarylamine and indoline are synthesized for dye-sensitized solar ceils （DSCs） employing cobalt and iodine redox shuttles. The effects of dye structure upon the photophysical, electro-chemical characteristics and cell perfor- mance are investigated. XS51 with four hexyloxyl groups on triarylamine performs better steric hindrance and an improvement of photovoltage. X852 provides higher short-circuit photocurrent density due to the strong electron-donating capability of indoline unit. The results from the redox electrolyte on cell performances indicate that the synthesized dyes are more suitable for tris（1,10-phenanthroline）cobalt（II/III） redox couple than I-/I3- redox couple in assembling DSCs. Application of X852 in the cobalt electrolyte yields a DSC with an overall power conversion efficiency of 6.58% under AM 1.5 （100 mW/cm2） irradiation.
基金Projects(L2014051,LT2014004)supported by the Program for Scientific Technology Plan of the Educational Department of Liaoning Province,China
文摘The structural, elastic, electronic and optical properties for U3Si2-type AlSc2Si2 compound under pressure were systematically investigated by using the first-principles calculations. The values of elastic constants and elastic moduli indicate that AlSc2Si2 keeps mechanical stability under high pressure. The mechanical properties of AISc2Si2 are compared with those of Al3Sc. The results indicate that AlSc2Si2 is harder than AI3Sc. Anisotropic constant AU and 3D curved surface of elastic moduli predict that AISc2Si2 is obviously anisotropic under pressure. The electronic structure of AlSc2Si2 exhibits metallic character and the metallicity decreases with the elevated pressure. In addition, optical properties as a function of pressure were calculated and analyzed. The present work provides theoretical support for further experimental work and industrial applications.
基金the Ministry of Science,Technological Development and Innovation of the Republic of Serbia(No.451-03-47/2023-01/200017)the PhD fellowship of Slađana LAKETIĆ.Authors would also like to acknowledge the help of Dr.Anton HOHENWARTER from the Department of Materials Science,Montanuniversitat Leoben,Austria,during the Ti−45Nb alloy microstructural analysis.
文摘The Ti−45Nb(wt.%)alloy properties were investigated in relation to its potential biomedical use.Laser surface modification was utilized to improve its performance in biological systems.As a result of the laser treatment,(Ti,Nb)O scale was formed and various morphological features appeared on the alloy surface.The electrochemical behavior of Ti−45Nb alloy in simulated body conditions was evaluated and showed that the alloy was highly resistant to corrosion deterioration regardless of additional laser surface modification treatment.Nevertheless,the improved corrosion resistance after laser treatment was evident(the corrosion current density of the alloy before laser irradiation was 2.84×10^(−8)A/cm^(2),while that after laser treatment with 5 mJ was 0.65×10^(−8)A/cm^(2))and ascribed to the rapid formation of a complex and passivating bi-modal surface oxide layer.Alloy cytotoxicity and effects of the Ti−45Nb alloy laser surface modification on the MRC-5 cell viability,morphology,and proliferation were also investigated.The Ti−45Nb alloy showed no cytotoxic effect.Moreover,cells showed improved viability and adherence to the alloy surface after the laser irradiation treatment.The highest average cell viability of 115.37%was attained for the alloy laser-irradiated with 15 mJ.Results showed that the laser surface modification can be successfully utilized to significantly improve alloy performance in a biological environment.
文摘A series of CH2, NH, O, and Se substituted 2,1,3-benzothiadiazote derivatives have been designed and investigated computationally to elucidate their potential as organic light-emitting materials for organic light-emitting diodes. Both ab initio Hartree-Foek and hybrid density functional methods are used. It is found that S by CH2, NH, O, and Se makes it possible transport properties of the pristine molecule adjusting the central aromatic ring by replacing to fine-tune the electronic, optical, and charge
基金Project(2012FU125X03)supported by Open Research Fund Project of National Engineering Research Center of SeafoodChina+3 种基金Project(2011–191)supported by the Key Science and Technology Platform of Liaoning Provincial Education DepartmentChinaProject(2010–354)supported by the Science and Technology Platform of DalianChina
文摘Ho^3＋-doped titanium dioxide（TiO2：Ho^3＋） downconversion（DC） nanowires were synthesized through a simple hydrothermal method followed by a subsequent calcination process after being immersed in Ho（NO3）3 aqueous solution. Moreover, TiO2：Ho^3＋ nanowires（HTNWs） were used as the photoanode in dye-sensitized solar cells（DSSCs） to investigate their photoelectric properties. Scanning electron microscopy（SEM） and X-ray diffraction（XRD） were used to characterize the morphology and structure of the material, respectively. The photofluorescence and ultraviolet-visible absorption spectra of HTNWs reveal a DC from the near and middle ultraviolet light to visible light which matches the strong absorbed region of the N719 dye. Compared with the pure TNW photoanode, HTNWs DC photoanodes show greater photovoltaic efficiency. The photovoltaic conversion efficiency（η） of the DSSCs with HTNWs photoanode doped with 4% Ho2O3（mass fraction） is two times that with pure TNW photoanode. This enhancement could be attributed to HTNWs which could extend the spectral response range of DSSCs to the near and middle ultraviolet region and increase the short-circuit current density（Jsc） of DSSCs, thus leading to the enhancement of photovoltaic conversion efficiency.
文摘Laser-weldable Sip-SiCp/Al hybrid composites with high volume fraction （60%-65%） of SiC reinforcement were fabricated by compression moulding and vacuum gas pressure infiltration technology. Microscopic observation displayed that the Sip-SiCp/Al hybrid composites with bilayer structure were compact without gas pores and the intergradation between Sip/Al layer and SiCp/Al layer was homogeneous and continuous. Further investigation revealed that the Sip-SiCp/Al hybrid composites possessed low density （2.96 g/cm^3）, high gas tightness （1.0 mPa·cm^3）/s）, excellent thermal management function as a result of high thermal conductivity （194 W/（m·K） and low coefficient of thermal expansion （7.0×10^-6 K-1）. Additionally, Sip-SiCp/Al hybrid composites had outstanding laser welding adaptability, which is significantly important for electronic packaging applications. The gas tightness of components after laser welding （48 mPa·cm^3）/s） can well match the requirement of advanced electronic packaging. Several kinds of these precision components passed tests and were put into production.
基金Project(cstc2011jj A50008)supported by the Natural Science Foundation of Chongqing,ChinaProject(14ZB0025)supported by Education Department of Sichuan Province,China
文摘Zn-doped TiO2 (Zn?TiO2) thin films were prepared by the sol?gel method on titanium substrates with heat treatment at different temperatures. The effects of heat treatment temperatures and Zn doping on the structure, photocathodic protection and photoelectrochemical properties of TiO2 thin films were investigated. It is indicated that the photoelectrical performance of the Zn?TiO2 films is enhanced with the addition of Zn element compared with the pure-TiO2 film and the largest decline by 897 mV in the electrode potential is achieved under 300 °C heat treatment. SEM?EDS analyses show that Zn element is unevenly distributed in Zn?TiO2 films; XRD patterns reveal that the grain size of Zn?TiO2 is smaller than that of pure-TiO2; FTIR results indicate that Zn - O bond forms on Zn?TiO2 surface. Ultraviolet visible absorption spectra prove that Zn?TiO2 shifts to visible light region.Mott?Shottky curves show that the flat-band potential of Zn?TiO2 is more negative and charge carrier density is bigger than that ofpure-TiO2, implying that under the synergy of the width of the space-charge layer, carrier density and flat-band potential, Zn?TiO2 with 300 °C heat treatment displays the best photocathodic protection performance.
基金Project(11264024)supported by the National Natural Science Foundation of ChinaProjects(2015MS0102,2015MS0524)supported by Natural Science Foundation of Inner Mongolia,China
文摘From the UV?Vis absorption spectra,the FT-IR absorption spectra and the Raman spectra,it is deduced that Co ionsprimarily occupy the tetrahedral(A)site,with a minor number of them entering into the octahedral(B)site in the Ni1?xCoxCr2O4compounds.The origin of the position disorder of the Co ions is consistent with the similar ionic radii of the Co ion(0.65?)and theCr ion(0.62?)at B site.The FT-IR peak at about510cm?1shifts towards high frequency side with the increasing cobalt content.Itis resulted from the reduction of the cation?oxygen distance in the octahedron by the replacement of the Ni2+with the Co2+ions.Themagnetic measurement shows that Curie temperatures(TC)are75and90K for the compounds with x=0.2and0.8,respectively.
文摘Er-doped BiVO4 composite photocatalyst was hydrothermal synthesized and characterized by X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray Spectroscopy, X-ray photoelectron spectroscopy, and UV-Vis diffuse reflectance spectra techniques. The activity of the catalyst was determined by oxidative decomposition of methyl orange in aqueous solution under visible-light irradiation. X-ray photoelectron spectroscopy and energy-dispersive X-ray Spectroscopy analysis revealed that the doped Er existed in the form of Er2O3. It also showed that the Er doping can enhance the visible-light absorption abilities of catalysts and their visible-light-driven photocatalytic activities in comparison with those of pure BiVO4.
基金Project(2018M632797)supported by the Postdoctoral Science Foundation of ChinaProject(52004253)supported by the National Natural Science Foundation of China。
文摘In this study,a high-purity In_(2)Ga_(2)ZnO_(7) ceramic target was used to deposit indium gallium zinc oxide(IGZO)films by RF magnetron sputtering technology.The microstructure,growth state,optical and electrical properties of the IGZO films were studied.The results showed that the surface of the IGZO film was uniform and smooth at room temperature.As the substrate temperature increased,the surface roughness of the film gradually increased.From room temperature to 300℃,all the films maintained amorphous phase and good thermal stabilities.Moreover,the transmission in the visible region decreased from 91.93%to 91.08%,and the band gap slightly decreased from 3.79 to 3.76 eV.The characterization of the film via atomic force microscope(AFM)and X-ray photoelectron spectroscopy(XPS)demonstrated that the film prepared at room temperature exhibited the lowest surface roughness and the largest content of oxygen vacancies.With the rise in temperature,the non-homogeneous particle distribution,increase in the surface roughness,and reduction in the number of oxygen vacancies resulted in lower performance of theα-IGZO film.Comprehensive analysis showed that the best optical and electrical properties can be obtained by depositing IGZO films at room temperature,which indicates their potential applications in flexible substrates.
文摘Al-doped ZnO(AZO)thin films were deposited on glass substrates by rf-sputtering at room temperature.The effects of substrate rotation speed(ωS)on the morphological,structural,optical and electrical properties were investigated.SEM transversal images show that the substrate rotation produces dense columnar structures which were found to be better defined under substrate rotation.AFM images show that the surface particles of the samples formed under substrate rotation are smaller and denser than those of a stationary one,leading to smaller grain sizes.XRD results show that all films have hexagonal wurtzite structure and preferred c-axis orientation with a tensile stress along the c-axis.The average optical transmittance was above90%in UV-Vis region.The lowest resistivity value(8.5×10?3Ω·cm)was achieved atωS=0r/min,with a carrier concentration of1.8×1020cm?3,and a Hall mobility of4.19cm2/(V·s).For all other samples,the substrate rotation induced changes in the carrier concentration and Hall mobility which resulted in the increasing of electrical resistivity.These results indicate that the morphology,structure,optical and electrical properties of the AZO thin films are strongly affected by the substrate rotation speed.
文摘The electro-physical properties of thin layers of rhenium chalcogenides＇ alloys, their dynamical and static ampere-voltaic characteristics were investigated. During the investigation of static and dynamical ampere-voltaic characteristics of rectifying contact of aluminium and rhenium chalcogenides＇ alloys the switching effects were found.
基金supported by the Natural Science Foundation of Liaoning Province(No.20170540086)the Open Fund of the State Key Laboratory of Molecular Reaction Dynamics in Dalian Institute of Chemical Physics,Chinese Academy of Sciences(SKLMRD-K202107,K202216)。
文摘The quality of perovskite layers has a great impact on the performance of perovskite solar cells(PSCs).However,defects and related trap sites are generated inevitably in the solutionprocessed polycrystalline perovskite films.It is meaningful to reduce and passivate the defect states by incorporating additive into the perovskite layer to improve perovskite crystallization.Here an environmental friendly 2D nanomaterial protonated graphitic carbon nitride(p-g-C_(3)N_(4))was successfully synthesized and doped into perovskite layer of carbon-based PSCs.The addition of p-g-C_(3)N_(4)into perovskite precursor solution not only adjusts nucleation and growth rate of methylammonium lead tri-iodide(MAPb I3)crystal for obtaining flat perovskite surface with larger grain size,but also reduces intrinsic defects of perovskite layer.It is found that thep-g-C_(3)N_(4) locates at the perovskite core,and the active groups-NH_(2)/NH_(3)and NH have a hydrogen bond strengthening,which effectively passivates electron traps and enhances the crystal quality of perovskite.As a result,a higher power conversion efficiency of 6.61% is achieved,compared with that doped with g-C_(3)N_(4)(5.93%)and undoped one(4.48%).This work demonstrates a simple method to modify the perovskite film by doping new modified additives and develops a low-cost preparation for carbon-based PSCs.
文摘The thickness of TiO2 film is vital to realize the optimization on photovoltaic performance of dye sensitized solar cells （DSSCs）. Herein, the process of charge separation in DSSCs was simulated by using a drift-diffusion model. This model allows multiple-trapping diffu- sion of photo-generated electrons, as well as the back reaction with the electron acceptors in electrolyte, to be mimicked in both steady and non-steady states. Numerical results on current-voltage characteristics allow power conversion efficiency to be maximized by varying the thickness of TiO2 film. Charge collection efficiency is shown to decrease with film thick- ness, whereas the flux of electron injection benefits from the film thickening. The output of photocurrent is actually impacted by the two factors. Furthermore, recombination rate constant is found to affect the optimized film thickness remarkably. Thicker TiO2 film is suitable to the DSSCs in which back reaction is suppressed sufficiently. On the contrary, the DSSCs with the redox couple showing fast electron interception require thinner film to alleviate the charge loss via recombination. At open circuit, electron density is found to decrease with film thickness, which engenders not only the reduction of photovoltage but also the increase of electron lifetime.
