The film morphology of dodecyl/carboxyl modified polysiloxane(RCAS) on cotton fabric or the silicon wafer was investigated and characterized by field emission scanning electron microscopy(FESEM),atomic force microscop...The film morphology of dodecyl/carboxyl modified polysiloxane(RCAS) on cotton fabric or the silicon wafer was investigated and characterized by field emission scanning electron microscopy(FESEM),atomic force microscope(AFM),and Fourier transform infrared spectrometer(FTIR).Experimental results indicate that RCAS is a good film forming material on different substrates.Relatively smooth film was formed on cotton fabric surface,on which the grooves disappeared.In addition,RCAS formed a micromorphology inhomogeneous and unsmooth film on the silicon wafer.Many high or low bright peaks distributed randomly on the film surface,especially as the field was 2μm×2 μm and the date scale was 5 nm in AFM observation.Then RCAS was emulsified with nonionic surfactant alkyl polyoxyethylene ether in order to achieve a transparent organosilicon emulsion-RCAS emulsion(RCSE),which possessed good stability.The properties of RCSE and its application performance on cotton fabrics were investigated and characterized by transmission electron microscope(TEM),particle size analysis,and voltage test instrument.The results show that the average particle size of RCAS emulsion is 28.32 nm,while the ζ voltage is-37.88 mV.Compared with untreatd cotton fabric,the softness of treated fabric can be improved with RCSE to a certain extent.At the same time,the fabric treated with RCSE acquires unique fluffy and soft handle.展开更多
We demonstrate a general approach for attaining the bottom morphology of block copolymer（BCP） thin films. In our former measurements on PS-b-PMMA films, surface morphology maps of the BCP films revealed distinct ord...We demonstrate a general approach for attaining the bottom morphology of block copolymer（BCP） thin films. In our former measurements on PS-b-PMMA films, surface morphology maps of the BCP films revealed distinct ordering regimes where the cylinders orient predominantly perpendicular or parallel to the interface and an ‘intermediate＇ regime where these morphologies coexist. However, this earlier work did not explore the bottom morphology of BCP thin films. In this study, we investigated the block copolymer morphology near the solid substrate in the cast block copolymer film having a perpendicular cylinder morphology on the surface.展开更多
Interfaces play critical roles in electronic devices and provide great diversity of film morphology and device performance.We retrospect the substrate mediated vacuum film growth of benchmark high mobility material 2,...Interfaces play critical roles in electronic devices and provide great diversity of film morphology and device performance.We retrospect the substrate mediated vacuum film growth of benchmark high mobility material 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene(C8-BTBT)and the interface electronic structures.The film growth of C8-BTBT molecules is diversified depending on the substrate-molecule and molecule-molecule interactions.On atomic smooth substrates C8-BTBT film grows in layer-by-layer mode while on coarse substrate it grows in islands mode.The initial molecular layer at dielectric,semiconductor and conductive substrates displays slight different lattice structure.The initial molecule orientation depends on the substrate and will gradually change to standing up configuration as in bulk phase.C8-BTBT behaves as electron donor when contacting with dielectric and stable conductive materials.This usually induces a dipole layer pointing to C8-BTBT and an upward bend bending in C8-BTBT side toward the interface.Although it is air stable,C8-BTBT is chemically reactive with some transition metals and compounds.The orientation change from lying down to standing up in the film usually leads to decrease of ionization potential.The article provides insights to the interface physical and chemical processes and suggestions for optimal design and fabrication of C8-BTBT based devices.展开更多
Basing on TGA (thermal gravimetric analysis) of thermal nitridation at l200, l250, l300℃, respectively, analysis of high temperature kinetics for nitridation of silicon monocrystal has been carried out. According to ...Basing on TGA (thermal gravimetric analysis) of thermal nitridation at l200, l250, l300℃, respectively, analysis of high temperature kinetics for nitridation of silicon monocrystal has been carried out. According to the theory for kinetics of reaction of vapour with solid phase a nitridation kinetic model, from which it can be shown thal the rate of nitridation reaction of silicon crystal should be controlled by three stage limiting factors, was proposed. These limiting factors are chemical reaction, chemical reaction mixed with diffusion and diffu- sion. Using this model to treat our experimental data, satisfactory correlation coefficient and apparent activation energy of nitridation of p-type (lll) silicon crystal have been obtained. The nitride film was identi' fied to be a-Si_3N_4 (Hexagonal, a=0.7758nm,c_o=0.5623nm) by X-ray diffraction analysis. Morphology of the nitride films formed in different nitridation duration was observed in both planar andcross-sectional views by SEM (scanning electron microscope).展开更多
1. Introduction Thermal oxidation of silicon monocrystalis a very important process in fabricationof metal--oxide--semiconductor (MOS) devices.In recent years it has received great atten-tion. Various proposals for ox...1. Introduction Thermal oxidation of silicon monocrystalis a very important process in fabricationof metal--oxide--semiconductor (MOS) devices.In recent years it has received great atten-tion. Various proposals for oxidation modeshave been made by different groups.Now most of the authors working in thisfield hold the view that the oxidation rateof silicon obeys a typical parabolic rule,that is, the oxidation reaction is controlledby diffusion. The experimental data inRef. can be taken and a kinetic curve展开更多
c-axis-oriented SmBa2Cu3O7（SmBCO） films have been deposited on（100）- LaA1O3（LAO）substrate by metal organic chemical vapor deposition（MOCVD） technique.The effects of deposition temperature（T（dep）） and total...c-axis-oriented SmBa2Cu3O7（SmBCO） films have been deposited on（100）- LaA1O3（LAO）substrate by metal organic chemical vapor deposition（MOCVD） technique.The effects of deposition temperature（T（dep）） and total pressure（P（tot）） on the orientation and microstructure of SmBCO films were investigated.The orientation of SmBCO films transformed from α-axis to c-axis with increasing of T（dep） from 900 to 1 100℃.At T（dep）=1 050℃,SmBCO films had c-axis orientation and tetragon surface.At P（tot）^（dep）=400-800 Pa and T（dep）=1 050 ℃,totally c-axis-oriented SmBCO films were obtained.The R（dep） of SmBCO films increased firstly and then decreased with increasing P（tot）.The surface of SmBCO films exhibited tetragon morphology at 1 050 ℃ and400 Pa.Maximum thickness of SmBCO film deposited was 1.2μm at P（tot）= 600 Pa,and the corresponding R（dep）was 7.2 μm·h^（-1）.展开更多
The morphology and structure of the oxide films of Ti in H3PO4 were investigated by galvanos tatic anodization, SEM and XRD. The oxide film grew from some pores in the grooves to layered microdomains as increasing ano...The morphology and structure of the oxide films of Ti in H3PO4 were investigated by galvanos tatic anodization, SEM and XRD. The oxide film grew from some pores in the grooves to layered microdomains as increasing anodizing voltage. The crystallinity of the oxide films decreased with the increase of the concentration of the electrolyte. The model has been proposed for the growth of the oxide films by two steps, i.e. by uniform thickening and by local deposition.展开更多
The surface morphology of buffer layer yttrium-stabilized zirconia （YSZ） of YBa2CuaO7-σ （YBCO） high temperature superconducting films relies on a series of controllable experimental parameters. In this work, we f...The surface morphology of buffer layer yttrium-stabilized zirconia （YSZ） of YBa2CuaO7-σ （YBCO） high temperature superconducting films relies on a series of controllable experimental parameters. In this work, we focus on the influence of pulsed laser frequency and target crystalline type on surface morphology of YSZ films deposited by pulsed laser deposition （PLD） on rolling assisted biaxially textured substrate tapes. Usually two kinds of particles are observed in the YSZ layer： randomly distributed ones on the whole film and self-assembled ones along grain boundaries. SEM images are used to prove that particles can be partly removed when choosing dense targets of single crystalline. Lower frequency of pulsed laser also contributes to a smoother film surface. TEM images are used to view the crystalline structure of thin film. Thus we can obtain a basic understanding of how to prepare a particle-free YSZ buffer layer for YBCO in optimized conditions using PLD. The YBCO layer with nice structure and critical current density of around 5 MA/cm2 can be reached on smooth YSZ samples.展开更多
By means of scanning electron microscope(SEM)and high voltage electron microscope(HVEM)we have observed and analysed morphology and micro-structure of silicon oxide film with different thickness formed on(111)silicon ...By means of scanning electron microscope(SEM)and high voltage electron microscope(HVEM)we have observed and analysed morphology and micro-structure of silicon oxide film with different thickness formed on(111)silicon monocrystal under dry oxygen atmosphere at 1100℃.Compared with their oxidation kinetic curves consisted of three stages,we suggested a mechanism on forming silicon oxide film.According to electron and X-ray diffraction analyses the silicon oxide films consisted of silica with different crystal structure.We also have discussed a stacking fault and a dislocation formed in the Si-Sio_2 interface region simulaneously forming silicon oxide film.展开更多
The effects of annealing temperature on the sol–gel-derived ZnO thin films deposited on n-Sh100 i substrates by sol–gel spin coating method have been studied in this paper.The structural,optical,and electrical prope...The effects of annealing temperature on the sol–gel-derived ZnO thin films deposited on n-Sh100 i substrates by sol–gel spin coating method have been studied in this paper.The structural,optical,and electrical properties of ZnO thin films annealed at 450,550,and 650 °C in the Ar gas atmosphere have been investigated in a systematic way.The XRD analysis shows a polycrystalline nature of the films at all three annealing temperatures.Further,the crystallite size is observed to be increased with the annealing temperature,whereas the positions of various peaks in the XRD spectra are found to be red-shifted with the temperature.The surface morphology studied through the scanning electron microscopy measurements shows a uniform distribution of ZnO nanoparticles over the entire Si substrates of enhanced grain sizes with the annealing temperature.Optical properties investigated by photoluminescence spectroscopy shows an optical band gap varying in the range of 3.28–3.15 eV as annealing temperature is increased from 450 to 650 °C,respectively.The fourpoint probe measurement shows a decrease in resistivity from 2：1 10 2to 8：1 10 4X cm with the increased temperature from 450 to 650 °C.The study could be useful for studying the sol–gel-derived ZnO thin film-based devices for various electronic,optoelectronic,and gas sensing applications.展开更多
Premature failure of coated tool often results from a poor adhesion of coating-substrate and shortens the lifetime of the tool. The results of increasing the adhesion strength of thin film coatings on cutting tool ins...Premature failure of coated tool often results from a poor adhesion of coating-substrate and shortens the lifetime of the tool. The results of increasing the adhesion strength of thin film coatings on cutting tool inserts by pretreating the inserts with sandblasting technique to obtain a desirable surface morphology of the inserts are presented. A geometric model representing the ideal surface morphology is established to enhance the nucleation density and adhesion strength of coating-substrate. Thin film coating experiment is conducted on the substrates of four different sample groups. Indentation and wear tests are performed on coated inserts to evaluate the effect of sandblasting on the adhesion strength of the coatings. A theoretical analysis is provided on the formation and growth of atom clusters in terms of the contact angle and the thermodynamic barrier of a substrate to predict thin film nucleation.展开更多
The effect of annealing temperature on the formation of the PtSi phase. distribution of silicides and the surface morphologies of silicides films is investigated by XPS. AFM. It is shown that the phase sequences of t...The effect of annealing temperature on the formation of the PtSi phase. distribution of silicides and the surface morphologies of silicides films is investigated by XPS. AFM. It is shown that the phase sequences of the films change from Pt-Pt2Si-PtSi-Si to Pt+Pt2Si+PtSi-PtSi-Si or Pt+Pt2Si+PtSi-PtSi-st with an increase of annealing temperature and the reason for the formation of mixed layers is discussed.展开更多
TiO2 thin film was prepared on Si substrate by plasma chemical vapor deposition （PCVD） system and the morphologies of ZiO2 thin film were controlled by adjusting the initial precursor concentration. As the initial t...TiO2 thin film was prepared on Si substrate by plasma chemical vapor deposition （PCVD） system and the morphologies of ZiO2 thin film were controlled by adjusting the initial precursor concentration. As the initial titanium tetra-isopropoxide （TTIP） concentration increases in PCVD reactor, the shapes of TiO2 particles generated in PCVD reactor change from the spherical small-sized particles around 20 nm and spherical large-sized particles around 60 nm to aggregate particles around 100 nm. The TiO2 particles with different shapes deposit on the substrate and become the main building blocks of resulting TiO2 thin film. We observed the TiO2 thin film with smooth morphology at low initial TTIP concentration, granular morphology at medium initial TTIP concentration, and columnar morphology at high initial TTIP concentration. It is proposed that we can prepare the TiO2 thin film with controlled morphologies in one-step process just by adjusting the initial precursor concentration in PCVD .展开更多
High-power pulsed magnetron sputtering(HPPMS)technology has drawn extensively attention for producing ultra-high dense plasma and high ionization fractions of the sputtered species,depositing dense films with high per...High-power pulsed magnetron sputtering(HPPMS)technology has drawn extensively attention for producing ultra-high dense plasma and high ionization fractions of the sputtered species,depositing dense films with high performance.CrNx films were deposited on the substrates of Si(100)using high-power pulsed unbalanced magnetron sputtering(HPPUMS)technology,and the analyses of XRD and atomic force microscope(AFM)were conducted on the properties of microstructure and surface morphology of CrNx films;the friction coefficient and the adhesion between CrNx film and substrate were measured,respectively.It was found HPPUMS discharge is able to deposit CrNx films with super comprehensive properties:higher adhesive strength between the film and substrate and lower coefficient of friction.Deposition rate of CrNx films,which was tested by interferometry,was about 4.2nm/min at 0.6Pa and the pulse power density up to 6.8kW/cm2 with the pulse repetition frequency of 0.7Hz,which is about 56%of that provided by the mid-frequency magnetron sputtering discharge under the conditions of the same average power output.However,clusters with a dimension of several hundred nanometers were observed on the AFM morphology probably related to high pulse current.展开更多
The CuxSi（1-x） thin films have been grown by pulsed laser deposition（PLD） with in situ annealing on Si（001） and Si（111）,respectively.The transformation of phase was detected by X-ray diffraction（XRD）.The res...The CuxSi（1-x） thin films have been grown by pulsed laser deposition（PLD） with in situ annealing on Si（001） and Si（111）,respectively.The transformation of phase was detected by X-ray diffraction（XRD）.The results showed that the as-deposited films were composed of Cu on both Si（001） and Si（111）.The annealed thin films consisted of Cu ＋η ＂-Cu3Si on Si（001） while Cu ＋η＇-Cu3Si on Si（111）,respectively,at annealed temperature（Ta）= 300-600℃.With the further increasing of Ta,at Ta= 700℃,there was only one main phase,η＂-Cu3Si on Si（001） while η＇-Cu3Si on Si（111）,respectively.The annealed thin films transformed from continuous dense structure to scattered-grain morphology with increasing Ta detected by field emission scanning electron microscope（FESEM）.It was also showed that the grain size would enlarge with increasing annealing time（ta）.展开更多
wo different surface morphology characteristics of magnetron sputtered aluminumsilicon(Al-Si)alloy films deposited at 0 and 200℃ were observed by atomic force microscopy(AFM).One is irregularly shaped grains put togt...wo different surface morphology characteristics of magnetron sputtered aluminumsilicon(Al-Si)alloy films deposited at 0 and 200℃ were observed by atomic force microscopy(AFM).One is irregularly shaped grains put togther on a plane.The other is irregularly shaped grains Piled up in space. Nanometer-sized particles with heights from 1.6 to 2.9 nm were first observed. On the basis of these observations the growth mechanism of magnetron sputtered films is discussed.展开更多
We have investigated homoepitaxy of Al N films grown by molecular beam epitaxy(MBE)on Al N/sapphire templates.The MBE epitaxy of Al N at the low temperature range,which is suitable for Al Ga N,encounters significant c...We have investigated homoepitaxy of Al N films grown by molecular beam epitaxy(MBE)on Al N/sapphire templates.The MBE epitaxy of Al N at the low temperature range,which is suitable for Al Ga N,encounters significant challenge in preventing Al droplet and pits,since the migration and desorption rate of Al atom are very low.In contrast,by elevating the growth temperature,such a difficulty can be effectively overcome,and we were able to grow Al N films with much improved surface morphology and obtained step flow growth mode without any Al droplets and pits.The cathodoluminescence spectroscopy indicate that the impurity incorporation and defect generation in the Al N epilayers was suppressed by elevating the growth temperature.A systematic investigation on the influence of Al beam flux and growth temperature in a very wide range on the Al N films has been conducted,and a comprehensive growth diagram of MBE Al N has been obtained.展开更多
Organic–inorganic halide perovskite(OIHP)solar cells have garnered great attention in the last decade since they continuously approach the Shockley–Queisser Limit.Compared with conventional organic and inorganic sem...Organic–inorganic halide perovskite(OIHP)solar cells have garnered great attention in the last decade since they continuously approach the Shockley–Queisser Limit.Compared with conventional organic and inorganic semiconductors,OIHPs possess the high tolerance on defects due to the dominated intrinsically shallow-level carrier-trapping centers.However,the existence of defects still causes the ion migration,produces the hysteresis effect,and accelerates the film degradation,eventually suppressing the device efficiency and stability.In this Review Article,we summarize recent impressive advance on passivating OIHP defects and discuss the future horizon of exploiting high-efficiency and long-stability OIHP solar cells in terms of defect managements.展开更多
Scalable printing of stretchable conjugated polymer films offers the opportunity to develop low-cost and large-area wearable electronics.However,achieving optimal film morphology to simultaneously improve energy dissi...Scalable printing of stretchable conjugated polymer films offers the opportunity to develop low-cost and large-area wearable electronics.However,achieving optimal film morphology to simultaneously improve energy dissipation and charge transport is still challenging for printed conjugated polymer films.Herein,we fabricate large-area stretchable conjugated polymer films with low crystallinity but strong chain alignment toward a high-performance wearable X-ray detector by simultaneously regulating fluid field and solidification dynamics during bar-coating.The strong fluid field aligns conjugated polymer chains in the coating direction and enhances solution aggregation in the initial wet layer,while sequential rapid solidification of the thin wet layer further restricts polymer crystallization but facilitates the alignment of aggregates,forming highly-aligned nanofiber networks within the elastomer phase.The elastomer-constrained nanofiber networks can further align with strain to maintain connectivity,providing an efficient charge transport channel during stretching.Consequently,the film shows high charge mobilities of 6.11 and 2.98 cm^(2)V^(−1)s^(−1)under 0%and 100%strains,among the highest values for stretchable conjugated polymer films.The designed film also exhibits a high sensitivity of 1757.2µC G_(yair)^(−1)cm^(−2)and an ultralow detection limit of 72.5 nG_(yair)s^(−1),maintaining good X-ray imaging capability before and after stretching.展开更多
A new A-B-A type of block copolymers,polyacrylonitrile-block-polydimethylsiloxane-block-polyacrylonitrile（PAN-b-PDMSb-PAN）,which comprises two polymer blocks of different polarities and compatibilities,were synthesi...A new A-B-A type of block copolymers,polyacrylonitrile-block-polydimethylsiloxane-block-polyacrylonitrile（PAN-b-PDMSb-PAN）,which comprises two polymer blocks of different polarities and compatibilities,were synthesized for the first time via reversible addition-fragmentation chain transfer polymerization.Reaction kinetics was investigated.PAN-b-PDMS-b-PAN films were prepared by spin-coating on glass chips.Significant order on the film surface morphologies was observed.展开更多
基金National Natural Science Foundation of China (No. 50373025)Doctoral Fund of the Ministry of Education of China (No.200807080002)Postgraduate Innovation Foundation of Shaanxi University of Science & Technology,China
文摘The film morphology of dodecyl/carboxyl modified polysiloxane(RCAS) on cotton fabric or the silicon wafer was investigated and characterized by field emission scanning electron microscopy(FESEM),atomic force microscope(AFM),and Fourier transform infrared spectrometer(FTIR).Experimental results indicate that RCAS is a good film forming material on different substrates.Relatively smooth film was formed on cotton fabric surface,on which the grooves disappeared.In addition,RCAS formed a micromorphology inhomogeneous and unsmooth film on the silicon wafer.Many high or low bright peaks distributed randomly on the film surface,especially as the field was 2μm×2 μm and the date scale was 5 nm in AFM observation.Then RCAS was emulsified with nonionic surfactant alkyl polyoxyethylene ether in order to achieve a transparent organosilicon emulsion-RCAS emulsion(RCSE),which possessed good stability.The properties of RCSE and its application performance on cotton fabrics were investigated and characterized by transmission electron microscope(TEM),particle size analysis,and voltage test instrument.The results show that the average particle size of RCAS emulsion is 28.32 nm,while the ζ voltage is-37.88 mV.Compared with untreatd cotton fabric,the softness of treated fabric can be improved with RCSE to a certain extent.At the same time,the fabric treated with RCSE acquires unique fluffy and soft handle.
基金financially supported by the National Natural Science Foundation of China(Nos.2127410321104054 and 21204059)the Undergraduate Innovation Project of Soochow University and the Project for Jiangsu Scientific and Technological Innovation team(2013)
文摘We demonstrate a general approach for attaining the bottom morphology of block copolymer（BCP） thin films. In our former measurements on PS-b-PMMA films, surface morphology maps of the BCP films revealed distinct ordering regimes where the cylinders orient predominantly perpendicular or parallel to the interface and an ‘intermediate＇ regime where these morphologies coexist. However, this earlier work did not explore the bottom morphology of BCP thin films. In this study, we investigated the block copolymer morphology near the solid substrate in the cast block copolymer film having a perpendicular cylinder morphology on the surface.
基金Project(2017YFA0206602)supported in part by the National Key Research and Development Program of China。
文摘Interfaces play critical roles in electronic devices and provide great diversity of film morphology and device performance.We retrospect the substrate mediated vacuum film growth of benchmark high mobility material 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene(C8-BTBT)and the interface electronic structures.The film growth of C8-BTBT molecules is diversified depending on the substrate-molecule and molecule-molecule interactions.On atomic smooth substrates C8-BTBT film grows in layer-by-layer mode while on coarse substrate it grows in islands mode.The initial molecular layer at dielectric,semiconductor and conductive substrates displays slight different lattice structure.The initial molecule orientation depends on the substrate and will gradually change to standing up configuration as in bulk phase.C8-BTBT behaves as electron donor when contacting with dielectric and stable conductive materials.This usually induces a dipole layer pointing to C8-BTBT and an upward bend bending in C8-BTBT side toward the interface.Although it is air stable,C8-BTBT is chemically reactive with some transition metals and compounds.The orientation change from lying down to standing up in the film usually leads to decrease of ionization potential.The article provides insights to the interface physical and chemical processes and suggestions for optimal design and fabrication of C8-BTBT based devices.
文摘Basing on TGA (thermal gravimetric analysis) of thermal nitridation at l200, l250, l300℃, respectively, analysis of high temperature kinetics for nitridation of silicon monocrystal has been carried out. According to the theory for kinetics of reaction of vapour with solid phase a nitridation kinetic model, from which it can be shown thal the rate of nitridation reaction of silicon crystal should be controlled by three stage limiting factors, was proposed. These limiting factors are chemical reaction, chemical reaction mixed with diffusion and diffu- sion. Using this model to treat our experimental data, satisfactory correlation coefficient and apparent activation energy of nitridation of p-type (lll) silicon crystal have been obtained. The nitride film was identi' fied to be a-Si_3N_4 (Hexagonal, a=0.7758nm,c_o=0.5623nm) by X-ray diffraction analysis. Morphology of the nitride films formed in different nitridation duration was observed in both planar andcross-sectional views by SEM (scanning electron microscope).
文摘1. Introduction Thermal oxidation of silicon monocrystalis a very important process in fabricationof metal--oxide--semiconductor (MOS) devices.In recent years it has received great atten-tion. Various proposals for oxidation modeshave been made by different groups.Now most of the authors working in thisfield hold the view that the oxidation rateof silicon obeys a typical parabolic rule,that is, the oxidation reaction is controlledby diffusion. The experimental data inRef. can be taken and a kinetic curve
基金Funded by National Natural Science Foundation of China(Nos.51102101,51272196,51372188,51521001)the 111 Project(No.B13035)+2 种基金International Science&Technology Cooperation Program of China(No.2014DFA53090)the Natural Science Foundation of Hubei Province,China(No.2014CFB870)the Fundamental Research Funds for the Central Universities,China(No.WUT:2015III023)
文摘c-axis-oriented SmBa2Cu3O7（SmBCO） films have been deposited on（100）- LaA1O3（LAO）substrate by metal organic chemical vapor deposition（MOCVD） technique.The effects of deposition temperature（T（dep）） and total pressure（P（tot）） on the orientation and microstructure of SmBCO films were investigated.The orientation of SmBCO films transformed from α-axis to c-axis with increasing of T（dep） from 900 to 1 100℃.At T（dep）=1 050℃,SmBCO films had c-axis orientation and tetragon surface.At P（tot）^（dep）=400-800 Pa and T（dep）=1 050 ℃,totally c-axis-oriented SmBCO films were obtained.The R（dep） of SmBCO films increased firstly and then decreased with increasing P（tot）.The surface of SmBCO films exhibited tetragon morphology at 1 050 ℃ and400 Pa.Maximum thickness of SmBCO film deposited was 1.2μm at P（tot）= 600 Pa,and the corresponding R（dep）was 7.2 μm·h^（-1）.
基金This work was supported by. tile grant uf Post-Doc.Program, Kylingpook National tjllivcrsity (if)IN)
文摘The morphology and structure of the oxide films of Ti in H3PO4 were investigated by galvanos tatic anodization, SEM and XRD. The oxide film grew from some pores in the grooves to layered microdomains as increasing anodizing voltage. The crystallinity of the oxide films decreased with the increase of the concentration of the electrolyte. The model has been proposed for the growth of the oxide films by two steps, i.e. by uniform thickening and by local deposition.
基金Supported by the ITER Project of the Ministry of Science and Technology of China under Grant No 2011GB113004the Shanghai Commission of Science and Technology under Grant No 11DZ1100402the Youth Fund of the National Natural Science Foundation of China under Grant No 11204174
文摘The surface morphology of buffer layer yttrium-stabilized zirconia （YSZ） of YBa2CuaO7-σ （YBCO） high temperature superconducting films relies on a series of controllable experimental parameters. In this work, we focus on the influence of pulsed laser frequency and target crystalline type on surface morphology of YSZ films deposited by pulsed laser deposition （PLD） on rolling assisted biaxially textured substrate tapes. Usually two kinds of particles are observed in the YSZ layer： randomly distributed ones on the whole film and self-assembled ones along grain boundaries. SEM images are used to prove that particles can be partly removed when choosing dense targets of single crystalline. Lower frequency of pulsed laser also contributes to a smoother film surface. TEM images are used to view the crystalline structure of thin film. Thus we can obtain a basic understanding of how to prepare a particle-free YSZ buffer layer for YBCO in optimized conditions using PLD. The YBCO layer with nice structure and critical current density of around 5 MA/cm2 can be reached on smooth YSZ samples.
文摘By means of scanning electron microscope(SEM)and high voltage electron microscope(HVEM)we have observed and analysed morphology and micro-structure of silicon oxide film with different thickness formed on(111)silicon monocrystal under dry oxygen atmosphere at 1100℃.Compared with their oxidation kinetic curves consisted of three stages,we suggested a mechanism on forming silicon oxide film.According to electron and X-ray diffraction analyses the silicon oxide films consisted of silica with different crystal structure.We also have discussed a stacking fault and a dislocation formed in the Si-Sio_2 interface region simulaneously forming silicon oxide film.
文摘The effects of annealing temperature on the sol–gel-derived ZnO thin films deposited on n-Sh100 i substrates by sol–gel spin coating method have been studied in this paper.The structural,optical,and electrical properties of ZnO thin films annealed at 450,550,and 650 °C in the Ar gas atmosphere have been investigated in a systematic way.The XRD analysis shows a polycrystalline nature of the films at all three annealing temperatures.Further,the crystallite size is observed to be increased with the annealing temperature,whereas the positions of various peaks in the XRD spectra are found to be red-shifted with the temperature.The surface morphology studied through the scanning electron microscopy measurements shows a uniform distribution of ZnO nanoparticles over the entire Si substrates of enhanced grain sizes with the annealing temperature.Optical properties investigated by photoluminescence spectroscopy shows an optical band gap varying in the range of 3.28–3.15 eV as annealing temperature is increased from 450 to 650 °C,respectively.The fourpoint probe measurement shows a decrease in resistivity from 2：1 10 2to 8：1 10 4X cm with the increased temperature from 450 to 650 °C.The study could be useful for studying the sol–gel-derived ZnO thin film-based devices for various electronic,optoelectronic,and gas sensing applications.
基金This project is Supported by National Science Foundation of China (No.59475090)National Science Foundation of USA (No.DDM-93-9669)
文摘Premature failure of coated tool often results from a poor adhesion of coating-substrate and shortens the lifetime of the tool. The results of increasing the adhesion strength of thin film coatings on cutting tool inserts by pretreating the inserts with sandblasting technique to obtain a desirable surface morphology of the inserts are presented. A geometric model representing the ideal surface morphology is established to enhance the nucleation density and adhesion strength of coating-substrate. Thin film coating experiment is conducted on the substrates of four different sample groups. Indentation and wear tests are performed on coated inserts to evaluate the effect of sandblasting on the adhesion strength of the coatings. A theoretical analysis is provided on the formation and growth of atom clusters in terms of the contact angle and the thermodynamic barrier of a substrate to predict thin film nucleation.
文摘The effect of annealing temperature on the formation of the PtSi phase. distribution of silicides and the surface morphologies of silicides films is investigated by XPS. AFM. It is shown that the phase sequences of the films change from Pt-Pt2Si-PtSi-Si to Pt+Pt2Si+PtSi-PtSi-Si or Pt+Pt2Si+PtSi-PtSi-st with an increase of annealing temperature and the reason for the formation of mixed layers is discussed.
基金supported by the Regional Innovation Center for Environmental Technology of Thermal Plasma(ETTP) at Inha University, designated by MKE(2009)supported from the Central Laboratory of Kangwon National University
文摘TiO2 thin film was prepared on Si substrate by plasma chemical vapor deposition （PCVD） system and the morphologies of ZiO2 thin film were controlled by adjusting the initial precursor concentration. As the initial titanium tetra-isopropoxide （TTIP） concentration increases in PCVD reactor, the shapes of TiO2 particles generated in PCVD reactor change from the spherical small-sized particles around 20 nm and spherical large-sized particles around 60 nm to aggregate particles around 100 nm. The TiO2 particles with different shapes deposit on the substrate and become the main building blocks of resulting TiO2 thin film. We observed the TiO2 thin film with smooth morphology at low initial TTIP concentration, granular morphology at medium initial TTIP concentration, and columnar morphology at high initial TTIP concentration. It is proposed that we can prepare the TiO2 thin film with controlled morphologies in one-step process just by adjusting the initial precursor concentration in PCVD .
基金the Cultivation Fund of the Key Scientific and Technical Innovation Project,Ministry of Education of China(No707015)NSFC(50407015)
文摘High-power pulsed magnetron sputtering(HPPMS)technology has drawn extensively attention for producing ultra-high dense plasma and high ionization fractions of the sputtered species,depositing dense films with high performance.CrNx films were deposited on the substrates of Si(100)using high-power pulsed unbalanced magnetron sputtering(HPPUMS)technology,and the analyses of XRD and atomic force microscope(AFM)were conducted on the properties of microstructure and surface morphology of CrNx films;the friction coefficient and the adhesion between CrNx film and substrate were measured,respectively.It was found HPPUMS discharge is able to deposit CrNx films with super comprehensive properties:higher adhesive strength between the film and substrate and lower coefficient of friction.Deposition rate of CrNx films,which was tested by interferometry,was about 4.2nm/min at 0.6Pa and the pulse power density up to 6.8kW/cm2 with the pulse repetition frequency of 0.7Hz,which is about 56%of that provided by the mid-frequency magnetron sputtering discharge under the conditions of the same average power output.However,clusters with a dimension of several hundred nanometers were observed on the AFM morphology probably related to high pulse current.
基金Funded by National Natural Science Foundation of China(Nos.51102101,51272196,51372188,51521001)the 111 Project(No.B13035)+2 种基金the International Science&Technology Cooperation Program of China(No.2014DFA53090)the Natural Science Foundation of Hubei Province,China(No.2014CFB870)the Fundamental Research Funds for the Central Universities,China(No.WUT:2015III023)
文摘The CuxSi（1-x） thin films have been grown by pulsed laser deposition（PLD） with in situ annealing on Si（001） and Si（111）,respectively.The transformation of phase was detected by X-ray diffraction（XRD）.The results showed that the as-deposited films were composed of Cu on both Si（001） and Si（111）.The annealed thin films consisted of Cu ＋η ＂-Cu3Si on Si（001） while Cu ＋η＇-Cu3Si on Si（111）,respectively,at annealed temperature（Ta）= 300-600℃.With the further increasing of Ta,at Ta= 700℃,there was only one main phase,η＂-Cu3Si on Si（001） while η＇-Cu3Si on Si（111）,respectively.The annealed thin films transformed from continuous dense structure to scattered-grain morphology with increasing Ta detected by field emission scanning electron microscope（FESEM）.It was also showed that the grain size would enlarge with increasing annealing time（ta）.
文摘wo different surface morphology characteristics of magnetron sputtered aluminumsilicon(Al-Si)alloy films deposited at 0 and 200℃ were observed by atomic force microscopy(AFM).One is irregularly shaped grains put togther on a plane.The other is irregularly shaped grains Piled up in space. Nanometer-sized particles with heights from 1.6 to 2.9 nm were first observed. On the basis of these observations the growth mechanism of magnetron sputtered films is discussed.
基金Project supported by the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0303400)the National Key Research and Development Program of China(Grant Nos.2022YFB3605602 and 2024YFE0205000)+1 种基金the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20243037)the Jiangsu Special Professorship,Collaborative Innovation Center of Solid-state Lighting and Energy-saving Electronics,Postdoctoral Fellowship Program of CPSF(Grant No.GZC20231098)。
文摘We have investigated homoepitaxy of Al N films grown by molecular beam epitaxy(MBE)on Al N/sapphire templates.The MBE epitaxy of Al N at the low temperature range,which is suitable for Al Ga N,encounters significant challenge in preventing Al droplet and pits,since the migration and desorption rate of Al atom are very low.In contrast,by elevating the growth temperature,such a difficulty can be effectively overcome,and we were able to grow Al N films with much improved surface morphology and obtained step flow growth mode without any Al droplets and pits.The cathodoluminescence spectroscopy indicate that the impurity incorporation and defect generation in the Al N epilayers was suppressed by elevating the growth temperature.A systematic investigation on the influence of Al beam flux and growth temperature in a very wide range on the Al N films has been conducted,and a comprehensive growth diagram of MBE Al N has been obtained.
文摘Organic–inorganic halide perovskite(OIHP)solar cells have garnered great attention in the last decade since they continuously approach the Shockley–Queisser Limit.Compared with conventional organic and inorganic semiconductors,OIHPs possess the high tolerance on defects due to the dominated intrinsically shallow-level carrier-trapping centers.However,the existence of defects still causes the ion migration,produces the hysteresis effect,and accelerates the film degradation,eventually suppressing the device efficiency and stability.In this Review Article,we summarize recent impressive advance on passivating OIHP defects and discuss the future horizon of exploiting high-efficiency and long-stability OIHP solar cells in terms of defect managements.
基金supported by the National Natural Science Foundation of China(52433009)the Fundamental Research Funds for the Central Universities(GK202501005)the Young Scientist Initiative Project of School of Materials Science and Engineering at Shaanxi Normal University(2024YSIP-MSE-SNNU012)。
文摘Scalable printing of stretchable conjugated polymer films offers the opportunity to develop low-cost and large-area wearable electronics.However,achieving optimal film morphology to simultaneously improve energy dissipation and charge transport is still challenging for printed conjugated polymer films.Herein,we fabricate large-area stretchable conjugated polymer films with low crystallinity but strong chain alignment toward a high-performance wearable X-ray detector by simultaneously regulating fluid field and solidification dynamics during bar-coating.The strong fluid field aligns conjugated polymer chains in the coating direction and enhances solution aggregation in the initial wet layer,while sequential rapid solidification of the thin wet layer further restricts polymer crystallization but facilitates the alignment of aggregates,forming highly-aligned nanofiber networks within the elastomer phase.The elastomer-constrained nanofiber networks can further align with strain to maintain connectivity,providing an efficient charge transport channel during stretching.Consequently,the film shows high charge mobilities of 6.11 and 2.98 cm^(2)V^(−1)s^(−1)under 0%and 100%strains,among the highest values for stretchable conjugated polymer films.The designed film also exhibits a high sensitivity of 1757.2µC G_(yair)^(−1)cm^(−2)and an ultralow detection limit of 72.5 nG_(yair)s^(−1),maintaining good X-ray imaging capability before and after stretching.
基金supported by the National Natural Science Foundation of China (No. 20874057)the Key Natural Science Foundation of Shandong Province of China (No. ZR2011BZ001)
文摘A new A-B-A type of block copolymers,polyacrylonitrile-block-polydimethylsiloxane-block-polyacrylonitrile（PAN-b-PDMSb-PAN）,which comprises two polymer blocks of different polarities and compatibilities,were synthesized for the first time via reversible addition-fragmentation chain transfer polymerization.Reaction kinetics was investigated.PAN-b-PDMS-b-PAN films were prepared by spin-coating on glass chips.Significant order on the film surface morphologies was observed.
