目的研究光电功能涂层制备方法对粉末薄膜光电极的光电转换效率的影响。方法采用喷涂法制备光电材料的FTO薄膜光电极,观察其表面形貌,通过研究光电流和光电位的变化评价光电材料的光电转换效率,并与点涂法和电泳法制备的光电极进行对比...目的研究光电功能涂层制备方法对粉末薄膜光电极的光电转换效率的影响。方法采用喷涂法制备光电材料的FTO薄膜光电极,观察其表面形貌,通过研究光电流和光电位的变化评价光电材料的光电转换效率,并与点涂法和电泳法制备的光电极进行对比分析。结果喷涂法制备的二氧化钛FTO薄膜光电极性能优于其他两种方法制备的电极,在3.5%氯化钠溶液中,光电位变化更稳定,压降大于500 m V,光电流变化大于60μA/cm^2。结论喷涂法制备光电极能够提高半导体粉末材料的光电化学效率,是一种可推行的薄膜光电极制备方法。展开更多
A novel WO3-x/TiO2 film as photoanode was synthesized for photoelectrocatalytic(PEC) reduction of CO2 into formic acid(HCOOH). The films prepared by doctor blade method were characterized with X-ray diffractometer...A novel WO3-x/TiO2 film as photoanode was synthesized for photoelectrocatalytic(PEC) reduction of CO2 into formic acid(HCOOH). The films prepared by doctor blade method were characterized with X-ray diffractometer(XRD), scanning electron microscope(SEM) and transmission electron microscope(TEM). The existence of oxygen vacancies in the WO3-x was confirmed with an X-ray photoelectron spectroscopy(XPS), and the accurate oxygen index was determined by a modified potentiometric titrimetry method. After 3h of photoelectrocatalytic reduction, the formic acid yield of the WO3-x/TiO2 film is 872 nmol/cm^2, which is 1.83 times that of the WO3/TiO2 film. The results of PEC performance demonstrate that the introduction of WO3-x nanoparticles can improve the charge transfer performance so as to enhance the performance of PEC reduction of CO2 into formic acid.展开更多
The effects of relative humidity (RH) on a printed circuit board finished with electroless nickel immersion gold (PCB-ENIG) under an adsorbed thin electrolyte layer (ATEL) were investigated in situ via the measurement...The effects of relative humidity (RH) on a printed circuit board finished with electroless nickel immersion gold (PCB-ENIG) under an adsorbed thin electrolyte layer (ATEL) were investigated in situ via the measurement of cathodic polarization curves, electrochemical impedance spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy to clearly elaborate the corrosion behavior of PCB-ENIG in the atmospheric environment. Results indicated that the cathodic process of PCB-ENIG under ATEL was dominated by the reduction of dissolved oxygen, corrosion products, and H2O. The cathodic current density of PCB-ENIG increased progressively with increasing RH. Moreover, its cathodic current density in the solution was greater than that under ATEL. This result demonstrated that the diffusion process was not the controlling step during the limiting reduction of cathodic oxygen. When the polarization potentials were located in a more negative region, the cathodic polarization current density gradually decreased under 75% and 85% RH. Notably, the anodic process became the controlling step in the extremely thin liquid film during the remainder of the experiment.展开更多
LiCo0.8M0.2O2 (M=Ni,Zr) films were fabricated by radio frequency sputtering deposition combined with conventional annealing methods. The strtuctures of the films were characterized with X-ray diffraction (XRD), Ra...LiCo0.8M0.2O2 (M=Ni,Zr) films were fabricated by radio frequency sputtering deposition combined with conventional annealing methods. The strtuctures of the films were characterized with X-ray diffraction (XRD), Raman spectroscopy and scarming electron microscopy (SEM) techniques. It was shown that the 700 ℃- annealed LiCo0.8M0.2O2 has an α-NaFeO2 like layered structure. All-solid-state thin-film batteries (TFBs) were fabrieated with these films as the cathode and their eleetroctemical performances were evaluated. It was found that doping of electrochemically active Ni and inactive Zr has different effects on the structural and elcctrochemical properties of the LiCoO2 cathode films. Ni doping increases the discharge capacity of the film while Zr doping improves its cycling stability.展开更多
Diamond like carbon thin film is successfully deposited on silicon, titanium and stainless steel substrate at low temperature in a filtered vacuum arc deposition system. Arc discharges are established on a graphite ...Diamond like carbon thin film is successfully deposited on silicon, titanium and stainless steel substrate at low temperature in a filtered vacuum arc deposition system. Arc discharges are established on a graphite cathode in the system with a toroidal macroparticle filter. A cathode activating magnetic field and a filtered magnetic field to collimate the plasma beam are applied. Ion current convected by the plasma beam is measured with a negatively biased probe. It is shown that the magnetic field of the coils located on the plasma duct has a strong influence on cathode spot behavior. Orthogonally the designed experiments are carried out to optimize the deposition parameters of arc stability. Finally, the diamond like carbon thin films are studied by scanning electron microscope (SEM) and Raman spectrum.展开更多
An organic thin-film transistor (OTFT) with an OTS/SiO2 bilayer gate insulator and a MoO3/AI electrode configuration between gate insulator and source/drain electrodes has been investigated. A thermally grown SiO2 l...An organic thin-film transistor (OTFT) with an OTS/SiO2 bilayer gate insulator and a MoO3/AI electrode configuration between gate insulator and source/drain electrodes has been investigated. A thermally grown SiO2 layer is used as the OTFT gate dielectric and copper phthalocyanine(CuPc) is used as an active layer. This OTS/SiO2 bilayer gate insulator configuration increases the field-effect mobility, reduces the threshold voltage, and improves the on/off ratio simultaneously. The device with a MoO3/Al electrode has shown similar Ids compared to the device with an Au electrode at the same gate voltage. Our results indicate that using a double-layer of electrodes and a double-layer of insulators is an effective way to improve OTFT performance.展开更多
Diamond like carbon (DLC) films was grown successfully on silicon, titanium and high speed steel (HSS) substrate at low temperature in a filtered vacuum arc deposition system. Arc discharges were established on a gra...Diamond like carbon (DLC) films was grown successfully on silicon, titanium and high speed steel (HSS) substrate at low temperature in a filtered vacuum arc deposition system. Arc discharges were established on a graphite cathode in this home built system with a toridal macroparticles filter. Ion current convected by the plasma beam was measured with a negatively biased probe. It was shown that the magnetic field of the coils located on the plasma duct has a strong influence on ion current. Scanning electron microscope (SEM), atomic force microscope (AFM) and Raman spectrum are used to study the DLC films. Tribological behaviors of the deposited film are also studied.展开更多
A novel device, lateral PIN photodiode gated by transparent electrode (LPIN PD-GTE) fabricated on fully-depleted SOI film was proposed. ITO film was adopted in the device as gate electrode to reduce the light absorp...A novel device, lateral PIN photodiode gated by transparent electrode (LPIN PD-GTE) fabricated on fully-depleted SOI film was proposed. ITO film was adopted in the device as gate electrode to reduce the light absorption. Thin Si film was fully depleted under gate voltage to achieve low dark current and high photo4o-dark current ratio. The model of gate voltage was obtained and the numerical simulations were presented by ATLAS. Current-voltage characteristics of LPIN PD-GTE obtained in dark (dark current) and under 570 nm illumination (photo current) were studied to achieve the greatest photo-to-dark current ratio for active channel length from 2 to 12 /am. The results show that the photo-to-dark current ratio is 2.0×10^7, with dark current of around 5×10^-4 pA under VGK=0.6 V, PrN=5 mW/cm2, for a total area of 10μm×10μm in fully depleted SOI technology. Thus, the LPIN PD-GTE can be suitable for high-grade photoelectric systems such as blue DVD.展开更多
An improved transverse Ising model is proposed by taking the depolarization field effect into account. Within the framework of mean-held theory we investigate the behavior of the ferroelectric thin film. Our results s...An improved transverse Ising model is proposed by taking the depolarization field effect into account. Within the framework of mean-held theory we investigate the behavior of the ferroelectric thin film. Our results show that the influence of the depolarization field is to flatten the spontaneous polarization profile and make the films more homogeneous, which is consistent with Ginzburg Landau theory. This fact shows that this model can be taken as an effective model to deal with the ferroelectric film and can be further extended to refer to quantum effect. The competition between quantum effect and depolarization field induces some interesting phenomena on ferroelectric thin films.展开更多
The hole injection,the radiative recombination and the device luminescent efficiencies of amorphous silicon carbide thin film p-i-n junction light emitting diodes are quantitatively calculated,and the effect of the ca...The hole injection,the radiative recombination and the device luminescent efficiencies of amorphous silicon carbide thin film p-i-n junction light emitting diodes are quantitatively calculated,and the effect of the carrier(especially the hole) injection and recombination processes on the device luminescent characteristics are revealed.Without considering the device junction temperature,it is found that the device luminescent efficiency mainly depends on the hole injection efficiency at low field and the hole radiative recombination efficiency at high field respectively.The theoretical analyses are in well agreement with the experimental results.展开更多
An electron transporting material of TFTTP (4-(5-hexylthiophene-2-yl)-2,6-bis(5-trifluoromethyl)thiophen-2-yl)pyridine) was investigated as a cathode buffer layer to enhance the power efficiency of organic sola...An electron transporting material of TFTTP (4-(5-hexylthiophene-2-yl)-2,6-bis(5-trifluoromethyl)thiophen-2-yl)pyridine) was investigated as a cathode buffer layer to enhance the power efficiency of organic solar cells (OSCs) based on subphthalocyanine and C60. The overall power conversion efficiency was increased by a factor of 1.31 by inserting the TFTTP interfacial layer between the active layer and metallic cathode. The inner mechanism responsible for the performance enhancement of OSCs was systematically studied with the simulation of dark diode behavior and optical field distribution inside the devices as well as the characterization of device photocurrent. The results showed that the TFTTP layer could significantly increase the built-in potential in the devices, leading to the enhanced dissociation of charge transfer excitons. In addition, by using TFTTP as the buffer layer, a better Ohmic contact at C60/metal interface was formed, facilitating more efficient free charge carrier collection.展开更多
Self-made TiO2 nanoparticles were used as photoelectrode material of dye sensitized solar cell. The TiO2 thin film coats through spreading nanoparticles evenly onto the ITO glass via self-made spin-heat platform, and ...Self-made TiO2 nanoparticles were used as photoelectrode material of dye sensitized solar cell. The TiO2 thin film coats through spreading nanoparticles evenly onto the ITO glass via self-made spin-heat platform, and then TiO2 thin film is soaked in the dye N-719 more than 12 h to prepare the photoelectrode device. The TiO2 nanoparticles produced by electric-discharge-nanofluid-process have premium anatase crystal property, and its diameter can be controlled within a range of 20-50 nm. The surface energy zeta potential of nanofluid is from -22 mV to -28.8 mV, it is a stable particle suspension in the deionized water. A trace of surfactant Triton X-100 put upon the surface of ITO glass can produce a uniform and dense TiO2 thin film and heating up the spin platform to 200 oC is able to eliminate mixed surfac-tant. Self-made TiO2 film presents excellent dye absorption performance and even doesn't need heat treatment procedure to enhance essential property. Results of energy analysis show the thicker film structure will increase the short-circuit current density that causes higher conversion efficiency. But, as the film structure is large and thick, both the open-circuit voltage and fill factor will decline gradually to lead bad efficiency of dye-sensitized solar cell.展开更多
We synthesized a mesoporous film based on TiO2-reduced graphene oxide(RGO)hybrids using a one-step vapor-thermal method without the need for an additional annealing process.The vapor-thermally prepared TiO2-graphene h...We synthesized a mesoporous film based on TiO2-reduced graphene oxide(RGO)hybrids using a one-step vapor-thermal method without the need for an additional annealing process.The vapor-thermally prepared TiO2-graphene hybrid(VTH)features unique structures with an ultra-large specific surface area of^260 m^2 g^-1 and low aggregation,giving rise to enhanced light harvesting and increased charge generation and separation efficiency.It was observed that a mesoporous film with uniform pore distribution is simultaneously obtained during the VTH growth process.When a 5.0 wt%RGO VTH film was used as the active layer in photocatalysis,the highest photocatalytic activity for degradation of methyl orange was achieved.For another,when a 0.75 wt%RGO VTH film was used as the photoanode in a dye-sensitized solar cell,the power conversion efficiency reached 7.58%,which represents an increase of 73.1%compared to a solar cell using an a photoanode of pure TiO2 synthesized by a traditional solvothermal method.It is expected that this facile method for the synthesis of TiO2/graphene hybrid mesoporous films will be useful in practical applications for preparing other metal oxide/graphene hybrids with ultra-high photocatalytic activity and photovoltaic performance.展开更多
文摘目的研究光电功能涂层制备方法对粉末薄膜光电极的光电转换效率的影响。方法采用喷涂法制备光电材料的FTO薄膜光电极,观察其表面形貌,通过研究光电流和光电位的变化评价光电材料的光电转换效率,并与点涂法和电泳法制备的光电极进行对比分析。结果喷涂法制备的二氧化钛FTO薄膜光电极性能优于其他两种方法制备的电极,在3.5%氯化钠溶液中,光电位变化更稳定,压降大于500 m V,光电流变化大于60μA/cm^2。结论喷涂法制备光电极能够提高半导体粉末材料的光电化学效率,是一种可推行的薄膜光电极制备方法。
基金Project(21471054)supported by the National Natural Science Foundation of China
文摘A novel WO3-x/TiO2 film as photoanode was synthesized for photoelectrocatalytic(PEC) reduction of CO2 into formic acid(HCOOH). The films prepared by doctor blade method were characterized with X-ray diffractometer(XRD), scanning electron microscope(SEM) and transmission electron microscope(TEM). The existence of oxygen vacancies in the WO3-x was confirmed with an X-ray photoelectron spectroscopy(XPS), and the accurate oxygen index was determined by a modified potentiometric titrimetry method. After 3h of photoelectrocatalytic reduction, the formic acid yield of the WO3-x/TiO2 film is 872 nmol/cm^2, which is 1.83 times that of the WO3/TiO2 film. The results of PEC performance demonstrate that the introduction of WO3-x nanoparticles can improve the charge transfer performance so as to enhance the performance of PEC reduction of CO2 into formic acid.
基金Project(51271032)supported by the National Natural Science Foundation of ChinaProject(2014CB643300)supported by the National Basic Research Program of ChinaProject supported by the National Environmental Corrosion Platform,China
文摘The effects of relative humidity (RH) on a printed circuit board finished with electroless nickel immersion gold (PCB-ENIG) under an adsorbed thin electrolyte layer (ATEL) were investigated in situ via the measurement of cathodic polarization curves, electrochemical impedance spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy to clearly elaborate the corrosion behavior of PCB-ENIG in the atmospheric environment. Results indicated that the cathodic process of PCB-ENIG under ATEL was dominated by the reduction of dissolved oxygen, corrosion products, and H2O. The cathodic current density of PCB-ENIG increased progressively with increasing RH. Moreover, its cathodic current density in the solution was greater than that under ATEL. This result demonstrated that the diffusion process was not the controlling step during the limiting reduction of cathodic oxygen. When the polarization potentials were located in a more negative region, the cathodic polarization current density gradually decreased under 75% and 85% RH. Notably, the anodic process became the controlling step in the extremely thin liquid film during the remainder of the experiment.
基金supported Science Foundation of China by the National Natural(No.20203006).
文摘LiCo0.8M0.2O2 (M=Ni,Zr) films were fabricated by radio frequency sputtering deposition combined with conventional annealing methods. The strtuctures of the films were characterized with X-ray diffraction (XRD), Raman spectroscopy and scarming electron microscopy (SEM) techniques. It was shown that the 700 ℃- annealed LiCo0.8M0.2O2 has an α-NaFeO2 like layered structure. All-solid-state thin-film batteries (TFBs) were fabrieated with these films as the cathode and their eleetroctemical performances were evaluated. It was found that doping of electrochemically active Ni and inactive Zr has different effects on the structural and elcctrochemical properties of the LiCoO2 cathode films. Ni doping increases the discharge capacity of the film while Zr doping improves its cycling stability.
文摘Diamond like carbon thin film is successfully deposited on silicon, titanium and stainless steel substrate at low temperature in a filtered vacuum arc deposition system. Arc discharges are established on a graphite cathode in the system with a toroidal macroparticle filter. A cathode activating magnetic field and a filtered magnetic field to collimate the plasma beam are applied. Ion current convected by the plasma beam is measured with a negatively biased probe. It is shown that the magnetic field of the coils located on the plasma duct has a strong influence on cathode spot behavior. Orthogonally the designed experiments are carried out to optimize the deposition parameters of arc stability. Finally, the diamond like carbon thin films are studied by scanning electron microscope (SEM) and Raman spectrum.
文摘An organic thin-film transistor (OTFT) with an OTS/SiO2 bilayer gate insulator and a MoO3/AI electrode configuration between gate insulator and source/drain electrodes has been investigated. A thermally grown SiO2 layer is used as the OTFT gate dielectric and copper phthalocyanine(CuPc) is used as an active layer. This OTS/SiO2 bilayer gate insulator configuration increases the field-effect mobility, reduces the threshold voltage, and improves the on/off ratio simultaneously. The device with a MoO3/Al electrode has shown similar Ids compared to the device with an Au electrode at the same gate voltage. Our results indicate that using a double-layer of electrodes and a double-layer of insulators is an effective way to improve OTFT performance.
文摘Diamond like carbon (DLC) films was grown successfully on silicon, titanium and high speed steel (HSS) substrate at low temperature in a filtered vacuum arc deposition system. Arc discharges were established on a graphite cathode in this home built system with a toridal macroparticles filter. Ion current convected by the plasma beam was measured with a negatively biased probe. It was shown that the magnetic field of the coils located on the plasma duct has a strong influence on ion current. Scanning electron microscope (SEM), atomic force microscope (AFM) and Raman spectrum are used to study the DLC films. Tribological behaviors of the deposited film are also studied.
基金Project(61040061) supported by the National Natural Science Foundation of ChinaProject supported by Hunan Provincial Innovation Foundation for Postgraduate Students,China
文摘A novel device, lateral PIN photodiode gated by transparent electrode (LPIN PD-GTE) fabricated on fully-depleted SOI film was proposed. ITO film was adopted in the device as gate electrode to reduce the light absorption. Thin Si film was fully depleted under gate voltage to achieve low dark current and high photo4o-dark current ratio. The model of gate voltage was obtained and the numerical simulations were presented by ATLAS. Current-voltage characteristics of LPIN PD-GTE obtained in dark (dark current) and under 570 nm illumination (photo current) were studied to achieve the greatest photo-to-dark current ratio for active channel length from 2 to 12 /am. The results show that the photo-to-dark current ratio is 2.0×10^7, with dark current of around 5×10^-4 pA under VGK=0.6 V, PrN=5 mW/cm2, for a total area of 10μm×10μm in fully depleted SOI technology. Thus, the LPIN PD-GTE can be suitable for high-grade photoelectric systems such as blue DVD.
文摘An improved transverse Ising model is proposed by taking the depolarization field effect into account. Within the framework of mean-held theory we investigate the behavior of the ferroelectric thin film. Our results show that the influence of the depolarization field is to flatten the spontaneous polarization profile and make the films more homogeneous, which is consistent with Ginzburg Landau theory. This fact shows that this model can be taken as an effective model to deal with the ferroelectric film and can be further extended to refer to quantum effect. The competition between quantum effect and depolarization field induces some interesting phenomena on ferroelectric thin films.
文摘The hole injection,the radiative recombination and the device luminescent efficiencies of amorphous silicon carbide thin film p-i-n junction light emitting diodes are quantitatively calculated,and the effect of the carrier(especially the hole) injection and recombination processes on the device luminescent characteristics are revealed.Without considering the device junction temperature,it is found that the device luminescent efficiency mainly depends on the hole injection efficiency at low field and the hole radiative recombination efficiency at high field respectively.The theoretical analyses are in well agreement with the experimental results.
文摘An electron transporting material of TFTTP (4-(5-hexylthiophene-2-yl)-2,6-bis(5-trifluoromethyl)thiophen-2-yl)pyridine) was investigated as a cathode buffer layer to enhance the power efficiency of organic solar cells (OSCs) based on subphthalocyanine and C60. The overall power conversion efficiency was increased by a factor of 1.31 by inserting the TFTTP interfacial layer between the active layer and metallic cathode. The inner mechanism responsible for the performance enhancement of OSCs was systematically studied with the simulation of dark diode behavior and optical field distribution inside the devices as well as the characterization of device photocurrent. The results showed that the TFTTP layer could significantly increase the built-in potential in the devices, leading to the enhanced dissociation of charge transfer excitons. In addition, by using TFTTP as the buffer layer, a better Ohmic contact at C60/metal interface was formed, facilitating more efficient free charge carrier collection.
文摘Self-made TiO2 nanoparticles were used as photoelectrode material of dye sensitized solar cell. The TiO2 thin film coats through spreading nanoparticles evenly onto the ITO glass via self-made spin-heat platform, and then TiO2 thin film is soaked in the dye N-719 more than 12 h to prepare the photoelectrode device. The TiO2 nanoparticles produced by electric-discharge-nanofluid-process have premium anatase crystal property, and its diameter can be controlled within a range of 20-50 nm. The surface energy zeta potential of nanofluid is from -22 mV to -28.8 mV, it is a stable particle suspension in the deionized water. A trace of surfactant Triton X-100 put upon the surface of ITO glass can produce a uniform and dense TiO2 thin film and heating up the spin platform to 200 oC is able to eliminate mixed surfac-tant. Self-made TiO2 film presents excellent dye absorption performance and even doesn't need heat treatment procedure to enhance essential property. Results of energy analysis show the thicker film structure will increase the short-circuit current density that causes higher conversion efficiency. But, as the film structure is large and thick, both the open-circuit voltage and fill factor will decline gradually to lead bad efficiency of dye-sensitized solar cell.
文摘We synthesized a mesoporous film based on TiO2-reduced graphene oxide(RGO)hybrids using a one-step vapor-thermal method without the need for an additional annealing process.The vapor-thermally prepared TiO2-graphene hybrid(VTH)features unique structures with an ultra-large specific surface area of^260 m^2 g^-1 and low aggregation,giving rise to enhanced light harvesting and increased charge generation and separation efficiency.It was observed that a mesoporous film with uniform pore distribution is simultaneously obtained during the VTH growth process.When a 5.0 wt%RGO VTH film was used as the active layer in photocatalysis,the highest photocatalytic activity for degradation of methyl orange was achieved.For another,when a 0.75 wt%RGO VTH film was used as the photoanode in a dye-sensitized solar cell,the power conversion efficiency reached 7.58%,which represents an increase of 73.1%compared to a solar cell using an a photoanode of pure TiO2 synthesized by a traditional solvothermal method.It is expected that this facile method for the synthesis of TiO2/graphene hybrid mesoporous films will be useful in practical applications for preparing other metal oxide/graphene hybrids with ultra-high photocatalytic activity and photovoltaic performance.