The performance of pearlescent pigment significantly affected by the grain size and the roughness of deposited film. The effect of TiCl_(4) concentration on the initial deposition of TiO_(2) on mica by atmospheric pre...The performance of pearlescent pigment significantly affected by the grain size and the roughness of deposited film. The effect of TiCl_(4) concentration on the initial deposition of TiO_(2) on mica by atmospheric pressure chemical vapor deposition(APCVD) was investigated. The precursor concentration significantly affected the deposition and morphology of TiO_(2) grains assembling the film. The deposition time for fully covering the surface of mica decreased from 120 to 10 s as the TiCl_(4) concentration increased from 0.38%to 2.44%. The grain size increased with the TiCl_(4) concentration. The AFM and TEM analysis demonstrated that the aggregation of TiO_(2) clusters at the initial stage finally result to the agglomeration of fine TiO_(2) grains at high TiCl_(4) concentrations. Following the results, it was suggested that the nucleation density and size was easy to be adjusted when the TiCl_(4) concentration is below 0.90%.展开更多
Epitaxial YBCO films were deposited on （100） LaAlO3 single-crystal substrates by metalorganic deposition of metal trifluoroacetate precursors with different concentrations. All the YBCO films have Tc around 91 K and...Epitaxial YBCO films were deposited on （100） LaAlO3 single-crystal substrates by metalorganic deposition of metal trifluoroacetate precursors with different concentrations. All the YBCO films have Tc around 91 K and Jc excess 2 MA/cm^2 at 77 K in zero field. XRD θ-2θscans show all the films have c-axis normal orientation. The FWHM （full width at half-maximum intensity） values of X-ray ω-scans of （005） reflection are 0.379°, 0.283°, and 0.543° for the YBCO thin films deposited with precursor solution concentrations of 1.52, 1.0, and 0.75 mol/L, respectively. With the concentration of the precursors decreasing, the thickness of the films decreases linearly. SEM micrographs show that porosities in the films become bigger with the precursor solution concentration decreasing. The big porosities in the film with the lowest concentration precursor deteriorate the superconducting property and make it have a wider superconducting transition and a lower Jc.展开更多
Pb0.97La0.02Zr0.95Ti0.05O3(PLZT)antiferroelectric thick films derived from different precursor solution concentrations are prepared on platinized silicon substrates by sol-gel processing.The films present polycrystall...Pb0.97La0.02Zr0.95Ti0.05O3(PLZT)antiferroelectric thick films derived from different precursor solution concentrations are prepared on platinized silicon substrates by sol-gel processing.The films present polycrystalline perovskite structure with a(100)preferred orientation by X-ray diffraction(XRD)analysis.The antiferroelectricity of the films is confirmed by the double hysteresis behaviors of polarization and double-bufferfly response of dielectric constant under the applied electrical field.Antiferroelectric properties and dielectric constant are improved while the polarization characteristic values are reduced with the increase of precursor solution concentration.The films at higher precursor solution concentration exhibit excellent dielectric properties.展开更多
Perovskite solar cells(PSCs)have rapidly emerged as a pivotal technology in the photovoltaic field due to their exceptional optoelectronic performance and low-cost fabrication processes[1–3].The unique structure of p...Perovskite solar cells(PSCs)have rapidly emerged as a pivotal technology in the photovoltaic field due to their exceptional optoelectronic performance and low-cost fabrication processes[1–3].The unique structure of perovskite materials endows them with excellent light absorption capabilities and efficient charge carrier transport properties,with certified power conversion efficiency(PCE)now surpassing 26%[4–6].展开更多
Transition metal dichalcogenide(TMD)alloys and heterostructures are attracting increasing attention thanks to their unique electronic,optical,and interfacial properties.However,the growth fundamental of TMD alloys and...Transition metal dichalcogenide(TMD)alloys and heterostructures are attracting increasing attention thanks to their unique electronic,optical,and interfacial properties.However,the growth fundamental of TMD alloys and heterostructures during one-step growth is still beyond understanding.Here,thermogravimetric(TG/DTG)technology is introduced to predict the evolution of the precursor(MoO_(3)and WO_(3))concentration in the vapor during growth.We establish the correlation between precursor concentration and the corresponding growth behavior.TG/DTG predication suggests that tuning precursor temperature and powder ratio can alter their concentration in the vapor,well explaining the formation of Mo_(x)W_(1-x)Se_(2) alloy or MoSe_(2)-WSe_(2) heterostructure at different growth conditions.Based on the TG/DTG analysis,we further design and grow a complex MoSe_(2)-Mo_(x)W_(1-x)Se_(2)-WSe_(2) heterostructure and Mo_(x)W_(1-x)Se_(2) monolayer alloys,confirming the validity of TG/DTG prediction in TMD crystal synthesis.Thus,employing TG/DTG to predict the synthesis of two-dimensional materials is of importance to understand the TMD growth behavior and provide guidance to the desired TMD heterostructure formation for future photoelectric devices.展开更多
Selective-controlled structure and shape of CeVO4 nanocrystals were successfully synthesized via a hydrothermal method from Na3VO4·12H2O and Ce（NO3）3·6H2O.The resulting products were characterized by X-ray...Selective-controlled structure and shape of CeVO4 nanocrystals were successfully synthesized via a hydrothermal method from Na3VO4·12H2O and Ce（NO3）3·6H2O.The resulting products were characterized by X-ray powder diffraction （XRD）,field emission scanning electron microscopy （FESEM） and energy dispersive spectroscopy （EDS）.The influence of hydrothermal temperature,precursor solution concentration on the crystal and morphology of products were further studied.The results showed that the as-synthesized products exhibited pure single-crystal CeVO4 nanoparticles with tetragonal structure.The hydrothermal temperature and precursor solution concentration had important effects on the formation of CeVO4 nanoparticles.Furthermore,the growth mechanism of CeVO4 nanoparticles was explained with Ostwald ripening mechanism.展开更多
Pure Ni nanoparticles ranging in size from 24 to 200nm are prepared via thermal decomposition of nickel acetylacetonate in oleylamine.The as-prepared Ni particles change from spherical to dendritic or starlike with in...Pure Ni nanoparticles ranging in size from 24 to 200nm are prepared via thermal decomposition of nickel acetylacetonate in oleylamine.The as-prepared Ni particles change from spherical to dendritic or starlike with increasing precursor concentration.The particles are stable because the organic coating occurs in situ.Magnetic measurement reveals that all the Ni nanoparticles are ferromagnetic and show ferromagnetic-paramagnetic transitions at their Curie points.The saturation magnetization Ms is size-dependent,with a maximum value of 52.01 and 82.31 emu/g at room temperature and 5 K,respectively.The coercivity decreases at first and then increases with increasing particle size,which is attributed to the competition between size effect and shape anisotropy.The Curie temperature Tc is 593,612,622,626 and 627 K for the 24,50,96,165 and 200 nm Ni nanoparticles,respectively.A theoretical model is proposed to explain the size-dependence of Ni nanoparticle Curie temperature.展开更多
The nanostructured titanium dioxide(TiO_(2))thin films have been prepared for the molar concentrations of titanium tetra isopropoxide(TTIP)0.05 M,0.1 M,0.15 M and 0.2 M by sol-gel routed spin coating technique with ca...The nanostructured titanium dioxide(TiO_(2))thin films have been prepared for the molar concentrations of titanium tetra isopropoxide(TTIP)0.05 M,0.1 M,0.15 M and 0.2 M by sol-gel routed spin coating technique with calcination at 450℃.The processing parameters such as,pH value(8),catalyst HCl(0.1 ml),spin speed(3000 rpm)and calcination temperature(450℃)are optimized.The crystalline nature and surface morphology were analyzed by XRD,SEM and AFM analysis.The XRD results confirm that the films are crystalline with anatase phase,and are nanostructured.The SEM micrographs of the TiO_(2) film reveal the spherical nature of the particle.AFM analysis establishes that the uniformity of the TiO_(2) thin film was optimized at 0.2 M.The optical measurements show that the transmittance depends on the molarity,and the optical band gap energy of TiO_(2) films is found to be inversely proportional to molarity.The I-V characteristics exhibit that the molarity strongly influences the electrical conductivity of the film.The results indicate that the significant effect of molarity on structural,optical and electrical properties of the nanostructured TiO_(2) thin films will be useful to photovoltaic application.展开更多
We systematically investigated the development of film morphology and crystallinity of methyl-ammonium bismuth （Ⅲ） iodide （MA3Bi2I9） through one- step spin-coating on TiO2-deposited indium tin oxide （ITO）/glass...We systematically investigated the development of film morphology and crystallinity of methyl-ammonium bismuth （Ⅲ） iodide （MA3Bi2I9） through one- step spin-coating on TiO2-deposited indium tin oxide （ITO）/glass. The precursor solution concentration and substrate structure have been demonstrated to be critically important in the active-layer evolution of the MA3Bi2I9-based solar cell. This work successfully improved the cell efficiency to 0.42% （average： 0.38%） with the mesoscopic architecture of ITO/compact-TiOdmesoscopic-TiO2 （meso-TiO2）/ MA3Bi2I9/2,2＇,7,7＇-tetrakis（N,N-di-4-methoxyphenylamino）-9,9＇spiro-bifluorene （spiro-MeOTAD）/MoO3/Ag under a precursor concentration of 0.45 M, which provided the probability of further improving the efficiency of the BiB＋-based lead-free organic-inorganic hybrid solar cells.展开更多
基金the support from National Natural Science Foundation of China (22208355, 22178363 and 21978300)the financial support and mica samples from Changzi Wu and RIKA technology CO., LTD.
文摘The performance of pearlescent pigment significantly affected by the grain size and the roughness of deposited film. The effect of TiCl_(4) concentration on the initial deposition of TiO_(2) on mica by atmospheric pressure chemical vapor deposition(APCVD) was investigated. The precursor concentration significantly affected the deposition and morphology of TiO_(2) grains assembling the film. The deposition time for fully covering the surface of mica decreased from 120 to 10 s as the TiCl_(4) concentration increased from 0.38%to 2.44%. The grain size increased with the TiCl_(4) concentration. The AFM and TEM analysis demonstrated that the aggregation of TiO_(2) clusters at the initial stage finally result to the agglomeration of fine TiO_(2) grains at high TiCl_(4) concentrations. Following the results, it was suggested that the nucleation density and size was easy to be adjusted when the TiCl_(4) concentration is below 0.90%.
文摘Epitaxial YBCO films were deposited on （100） LaAlO3 single-crystal substrates by metalorganic deposition of metal trifluoroacetate precursors with different concentrations. All the YBCO films have Tc around 91 K and Jc excess 2 MA/cm^2 at 77 K in zero field. XRD θ-2θscans show all the films have c-axis normal orientation. The FWHM （full width at half-maximum intensity） values of X-ray ω-scans of （005） reflection are 0.379°, 0.283°, and 0.543° for the YBCO thin films deposited with precursor solution concentrations of 1.52, 1.0, and 0.75 mol/L, respectively. With the concentration of the precursors decreasing, the thickness of the films decreases linearly. SEM micrographs show that porosities in the films become bigger with the precursor solution concentration decreasing. The big porosities in the film with the lowest concentration precursor deteriorate the superconducting property and make it have a wider superconducting transition and a lower Jc.
基金National Natural Science Foundation of China(No.60806039,No.51175483)China Postdoctoral Science Foundation Projects(No.20090461275,No.201003658)+1 种基金Shanxi Provincial Natural Science Foundation of China(No.20100210023-6)Shanxi Provincial Young Leaders on Science
文摘Pb0.97La0.02Zr0.95Ti0.05O3(PLZT)antiferroelectric thick films derived from different precursor solution concentrations are prepared on platinized silicon substrates by sol-gel processing.The films present polycrystalline perovskite structure with a(100)preferred orientation by X-ray diffraction(XRD)analysis.The antiferroelectricity of the films is confirmed by the double hysteresis behaviors of polarization and double-bufferfly response of dielectric constant under the applied electrical field.Antiferroelectric properties and dielectric constant are improved while the polarization characteristic values are reduced with the increase of precursor solution concentration.The films at higher precursor solution concentration exhibit excellent dielectric properties.
基金supported by the National Natural Science Foundation of China(52332008,52025028,52202273,52450138,and 52402294)the Natural Science Foundation of Jiangsu Province(BK20240820)+1 种基金the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutionsthe Youth Talent Lifting Project of the China Association for Science and Technology.
文摘Perovskite solar cells(PSCs)have rapidly emerged as a pivotal technology in the photovoltaic field due to their exceptional optoelectronic performance and low-cost fabrication processes[1–3].The unique structure of perovskite materials endows them with excellent light absorption capabilities and efficient charge carrier transport properties,with certified power conversion efficiency(PCE)now surpassing 26%[4–6].
基金The National Natural Science Foundation of Giina(Nos.51702368,61974166,and 11674401)the Natural Science Foundation of Hunan Province(Nos.2018JJ3684 and 2019JJ40358)+1 种基金Innovation-Driven Project of Central South University(No.2018CX045)the Mechanism Research Funds for the Central South University(No.1053320181264)are acknowledged for financial support.
文摘Transition metal dichalcogenide(TMD)alloys and heterostructures are attracting increasing attention thanks to their unique electronic,optical,and interfacial properties.However,the growth fundamental of TMD alloys and heterostructures during one-step growth is still beyond understanding.Here,thermogravimetric(TG/DTG)technology is introduced to predict the evolution of the precursor(MoO_(3)and WO_(3))concentration in the vapor during growth.We establish the correlation between precursor concentration and the corresponding growth behavior.TG/DTG predication suggests that tuning precursor temperature and powder ratio can alter their concentration in the vapor,well explaining the formation of Mo_(x)W_(1-x)Se_(2) alloy or MoSe_(2)-WSe_(2) heterostructure at different growth conditions.Based on the TG/DTG analysis,we further design and grow a complex MoSe_(2)-Mo_(x)W_(1-x)Se_(2)-WSe_(2) heterostructure and Mo_(x)W_(1-x)Se_(2) monolayer alloys,confirming the validity of TG/DTG prediction in TMD crystal synthesis.Thus,employing TG/DTG to predict the synthesis of two-dimensional materials is of importance to understand the TMD growth behavior and provide guidance to the desired TMD heterostructure formation for future photoelectric devices.
基金financial support by the Open Project Program of the State Key Laboratory of Solid Lu-brication, Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences (0804)
文摘Selective-controlled structure and shape of CeVO4 nanocrystals were successfully synthesized via a hydrothermal method from Na3VO4·12H2O and Ce（NO3）3·6H2O.The resulting products were characterized by X-ray powder diffraction （XRD）,field emission scanning electron microscopy （FESEM） and energy dispersive spectroscopy （EDS）.The influence of hydrothermal temperature,precursor solution concentration on the crystal and morphology of products were further studied.The results showed that the as-synthesized products exhibited pure single-crystal CeVO4 nanoparticles with tetragonal structure.The hydrothermal temperature and precursor solution concentration had important effects on the formation of CeVO4 nanoparticles.Furthermore,the growth mechanism of CeVO4 nanoparticles was explained with Ostwald ripening mechanism.
基金the National Natural Science Foundation of China(no.50801033)
文摘Pure Ni nanoparticles ranging in size from 24 to 200nm are prepared via thermal decomposition of nickel acetylacetonate in oleylamine.The as-prepared Ni particles change from spherical to dendritic or starlike with increasing precursor concentration.The particles are stable because the organic coating occurs in situ.Magnetic measurement reveals that all the Ni nanoparticles are ferromagnetic and show ferromagnetic-paramagnetic transitions at their Curie points.The saturation magnetization Ms is size-dependent,with a maximum value of 52.01 and 82.31 emu/g at room temperature and 5 K,respectively.The coercivity decreases at first and then increases with increasing particle size,which is attributed to the competition between size effect and shape anisotropy.The Curie temperature Tc is 593,612,622,626 and 627 K for the 24,50,96,165 and 200 nm Ni nanoparticles,respectively.A theoretical model is proposed to explain the size-dependence of Ni nanoparticle Curie temperature.
文摘The nanostructured titanium dioxide(TiO_(2))thin films have been prepared for the molar concentrations of titanium tetra isopropoxide(TTIP)0.05 M,0.1 M,0.15 M and 0.2 M by sol-gel routed spin coating technique with calcination at 450℃.The processing parameters such as,pH value(8),catalyst HCl(0.1 ml),spin speed(3000 rpm)and calcination temperature(450℃)are optimized.The crystalline nature and surface morphology were analyzed by XRD,SEM and AFM analysis.The XRD results confirm that the films are crystalline with anatase phase,and are nanostructured.The SEM micrographs of the TiO_(2) film reveal the spherical nature of the particle.AFM analysis establishes that the uniformity of the TiO_(2) thin film was optimized at 0.2 M.The optical measurements show that the transmittance depends on the molarity,and the optical band gap energy of TiO_(2) films is found to be inversely proportional to molarity.The I-V characteristics exhibit that the molarity strongly influences the electrical conductivity of the film.The results indicate that the significant effect of molarity on structural,optical and electrical properties of the nanostructured TiO_(2) thin films will be useful to photovoltaic application.
基金This work was supported by the National Basic Research Program of China （No. 2014CB643503）, the National Natural Science Foundation of China （Nos. 91233114, 51373151 Zhejiang Province Natural LR15E030001）. and 51261130582） and Science Foundation （No.
文摘We systematically investigated the development of film morphology and crystallinity of methyl-ammonium bismuth （Ⅲ） iodide （MA3Bi2I9） through one- step spin-coating on TiO2-deposited indium tin oxide （ITO）/glass. The precursor solution concentration and substrate structure have been demonstrated to be critically important in the active-layer evolution of the MA3Bi2I9-based solar cell. This work successfully improved the cell efficiency to 0.42% （average： 0.38%） with the mesoscopic architecture of ITO/compact-TiOdmesoscopic-TiO2 （meso-TiO2）/ MA3Bi2I9/2,2＇,7,7＇-tetrakis（N,N-di-4-methoxyphenylamino）-9,9＇spiro-bifluorene （spiro-MeOTAD）/MoO3/Ag under a precursor concentration of 0.45 M, which provided the probability of further improving the efficiency of the BiB＋-based lead-free organic-inorganic hybrid solar cells.
