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
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
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
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
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
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
Developments of economic systems are critical for bio-regenerative life support systems in manned space missions.In this work we report on the feasibility of using two direct sunlight powered processes sequentially fo...Developments of economic systems are critical for bio-regenerative life support systems in manned space missions.In this work we report on the feasibility of using two direct sunlight powered processes sequentially for the recovery of water and nutrients from urine.The work presents experimental evidence on nutrient and water recovery achieved using the proto-type designed and developed.We report the design and testing of a solar still which would serve on the nutrient recovery front.The cooled condensate from the solar still is fed into a solar powered electrolysis unit where nano-structured indium sulphide(In_(2)S_(3))thin films coated over fluorine doped tin oxide(SnO_(2):F)substrate serve as one of the working electrodes.The electrolysis takes place in the absence of an electrolyte which manifests as a technical achievement of our work.Our results show that the COD level in the recycled water is very low.The In_(2)S_(3)photo-electrodes are stable without any physical damage after the process.展开更多
The present paper discusses our investigation of InGaAs surface morphology annealed for different lengths of time.After annealing for 15 min,the ripening of InGaAs islands is completed.The real space scanning tunnelin...The present paper discusses our investigation of InGaAs surface morphology annealed for different lengths of time.After annealing for 15 min,the ripening of InGaAs islands is completed.The real space scanning tunneling microscopy(STM) images show the evolution of InGaAs surface morphology.A half-terrace diffusion theoretical model based on thermodynamic theory is proposed to estimate the annealing time for obtaining flat morphology.The annealing time calculated by the proposed theory is in agreement with the experimental results.展开更多
In a previous paper, we have reported the relationship between the crystallite orientation of the evaporated film of copper phthalacyanine (PcCu) (α-form) and the incident angle of molecular beam at 10-5 torr. In...In a previous paper, we have reported the relationship between the crystallite orientation of the evaporated film of copper phthalacyanine (PcCu) (α-form) and the incident angle of molecular beam at 10-5 torr. In this paper, we shall show some research results about vacuum effects on the crystal forms and the morphology of the evaporat-展开更多
Layered α-cobalt hydroxides Co(OH1.65 Cl0.35.0.5H2O (1), Co(OH)1.75(NO3)0.25.0.1H2O(2) with unique macro- and microscale morphologies have been synthesised by a low temperature, ammonia-controlled vapour-dif...Layered α-cobalt hydroxides Co(OH1.65 Cl0.35.0.5H2O (1), Co(OH)1.75(NO3)0.25.0.1H2O(2) with unique macro- and microscale morphologies have been synthesised by a low temperature, ammonia-controlled vapour-diffusion method. The materials have thin film morphologies and were characterized by X-ray powder diffraction (XRD) and field emission scanning electron microscopy (FESEM).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
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.
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.
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R.Jayakrishnan thanks KSCSTE for funding this work under the SPYTiS scheme(Grant No.25/SPYTiS III/2017/KSCSTE)also thanks DoECC,Government of Kerala for supporting the work(Grant No.DoECC/E3/R&D/1751/2017).
文摘Developments of economic systems are critical for bio-regenerative life support systems in manned space missions.In this work we report on the feasibility of using two direct sunlight powered processes sequentially for the recovery of water and nutrients from urine.The work presents experimental evidence on nutrient and water recovery achieved using the proto-type designed and developed.We report the design and testing of a solar still which would serve on the nutrient recovery front.The cooled condensate from the solar still is fed into a solar powered electrolysis unit where nano-structured indium sulphide(In_(2)S_(3))thin films coated over fluorine doped tin oxide(SnO_(2):F)substrate serve as one of the working electrodes.The electrolysis takes place in the absence of an electrolyte which manifests as a technical achievement of our work.Our results show that the COD level in the recycled water is very low.The In_(2)S_(3)photo-electrodes are stable without any physical damage after the process.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60866001 and 61076049)the Science and Technology Projects for Overseas Researchers of Guizhou Province (Grant No. (2007) 03)+5 种基金the Foundation of Guizhou Provincial Science and Technology Department (Grant No. QKH-J[2007]2176)the Special Assistant to the High-Level Personnel Research Projects of Guizhou Provincial Committee,Organization Department(Grant No. TZJF-200610)the Doctorate Foundation of the Education Ministry of China (Grant No. 20105201110003)the Science and Technology Projects for Overseas Researchers of Guizhou Province (Grant No. Z103233)Special Governor Fund for Outstanding Professionals in Science & Technology and Education of Guizhou Province (Grant No. 2009114)the Innovation Funds for Graduates of Guizhou University (Grant No. LG2012019)
文摘The present paper discusses our investigation of InGaAs surface morphology annealed for different lengths of time.After annealing for 15 min,the ripening of InGaAs islands is completed.The real space scanning tunneling microscopy(STM) images show the evolution of InGaAs surface morphology.A half-terrace diffusion theoretical model based on thermodynamic theory is proposed to estimate the annealing time for obtaining flat morphology.The annealing time calculated by the proposed theory is in agreement with the experimental results.
文摘In a previous paper, we have reported the relationship between the crystallite orientation of the evaporated film of copper phthalacyanine (PcCu) (α-form) and the incident angle of molecular beam at 10-5 torr. In this paper, we shall show some research results about vacuum effects on the crystal forms and the morphology of the evaporat-
文摘Layered α-cobalt hydroxides Co(OH1.65 Cl0.35.0.5H2O (1), Co(OH)1.75(NO3)0.25.0.1H2O(2) with unique macro- and microscale morphologies have been synthesised by a low temperature, ammonia-controlled vapour-diffusion method. The materials have thin film morphologies and were characterized by X-ray powder diffraction (XRD) and field emission scanning electron microscopy (FESEM).
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.