NiO films were fabricated by reactive direct current magnetron sputtering on glass and alumina substrates for the application in energetic nano-multilayers. The structural and thermal properties of the films were inve...NiO films were fabricated by reactive direct current magnetron sputtering on glass and alumina substrates for the application in energetic nano-multilayers. The structural and thermal properties of the films were investigated with the volume ratio of oxygen to argon ranging from 1：9 to 3：2, and the optimized ratio value is obtained as 1：3, which was confirmed by X-ray diffraction （XRD）, atomic force microscopy and ultrafast measure- ment system. The effect of the film thickness, varying from 150 to 900 nm, on the structural properties was characterized by XRD and scanning electron microscopy （SEM）. XRD analysis reveals that the （111） lattice plane is the preferred orientation. The intensities of preferential peaks and the grain sizes increase as the film thicknesses increase.展开更多
NiO,an anodic electrochromic material,has applications in energy-saving windows,intelligent displays,and military camouflage.However,its electrochromic mechanism and reasons for its performance degradation in alkaline...NiO,an anodic electrochromic material,has applications in energy-saving windows,intelligent displays,and military camouflage.However,its electrochromic mechanism and reasons for its performance degradation in alkaline aqueous electrolytes are complex and poorly understood,making it challenging to improve NiO thin films.We studied the phases and electrochemical characteristics of NiO films in different states(initial,colored,bleached and after 8000 cycles)and identified three main reasons for performance degradation.First,Ni(OH)_(2)is generated during electrochromic cycling and deposited on the NiO film surface,gradually yielding a NiO@Ni(OH)_(2)core-shell structure,isolating the internal NiO film from the electrolyte,and preventing ion transfer.Second,the core-shell structure causes the mode of electrical conduction to change from first-to second-order conduction,reducing the efficiency of ion transfer to the surface Ni(OH)_(2)layer.Third,Ni(OH)_(2)and NiOOH,which have similar crystal structures but different b-axis lattice parameters,are formed during electrochromic cycling,and large volume changes in the unit cell reduce the structural stability of the thin film.Finally,we clarified the mechanism of electrochromic performance degradation of NiO films in alkaline aqueous electrolytes and provide a route to activation of NiO films,which will promote the development of electrochromic technology.展开更多
By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering met...By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering method in pure argon and pure oxygen gas,respectively.The crystal structure,morphological characteristics,composition and optical properties of the obtained films were compared by X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and ultraviolet(UV)-visible spectrophotometer.The properties of the thin films deposited in different sputtering gases are quite different.For the films deposited in pure argon gas,it is a polycrystalline thin film with(200)preferred orientation,while the film deposited in pure oxygen has no preferred orientation.The grain size,molar ratio of Mg to Ni atoms and optical bandgap are larger for the films deposited in pure argon gas than those deposited in oxygen gas.展开更多
Inorganic metal oxide electrochromic materials have good application prospects for energy-saving windows in buildings and smart display applications.Therefore,the development of electrochromic films with good cycling ...Inorganic metal oxide electrochromic materials have good application prospects for energy-saving windows in buildings and smart display applications.Therefore,the development of electrochromic films with good cycling stabilities,fast color-change response times,and high coloring efficiencies has attracted considerable attention.In this study,nanoflake Li-doped NiO electrochromic films were prepared using a hydrothermal method,and the films exhibited superior electrochromic performances in the LiOH electrolyte.Li^(+)ions doping increased the ion transmission rates of the NiO films,and effectively promoted the transportation of ions from the electrolyte into NiO films.Meanwhile,the nanoflake microstructure caused the NiO films to have larger specific surface areas,providing more active sites for electrochemical reactions.It was determined that the NiO-Li20%film exhibited an ultra-fast response in the LiOH electrolyte(coloring and bleaching times reached 3 and 1.5 s,respectively).Additionally,the coloration efficiency was 62.1 cm^(2)C^(−1),and good cycling stability was maintained beyond 1500 cycles.Finally,the simulation calculation results showed that Li doping weakened the adsorption strengths of the NiO films to OH^(−),which reduced the generation and decomposition of NiOOH and helped to improve the cycling stabilities of the films.Therefore,the research presented in this article provides a strategy for designing electrochromic materials in the future.展开更多
As a convenient,low-cost and up-scalable solution route,chemical bath deposition(CBD)has exhibited impressive advantages in fabricating electron transporting materials like SnO_(2),achieving record efficien-cies for r...As a convenient,low-cost and up-scalable solution route,chemical bath deposition(CBD)has exhibited impressive advantages in fabricating electron transporting materials like SnO_(2),achieving record efficien-cies for regular n-i-p perovskite solar cells(PSCs).However,for the hysteresis-free and potentially more stable inverted p-i-n PSCs,CBD processing is rarely studied to improve the device performance.In this work,we first present a CBD planar NiO x film as the efficient hole transport layer for the inverted per-ovskite solar cells(IPSCs).The morphologies and semiconducting properties of the NiO x film can be ad-justed by varying the concentration of[Ni(H 2 O)x(NH 3)6-x]2+cation via in-situ monitoring of the CBD re-action process.The characterizations of ultraviolet photoelectron spectroscopy,transient absorption spec-troscopy,time-resolved photoluminescence suggest that the CBD planar NiO x film possesses enhanced conductivity and aligned energy band levels with perovskite,which benefits for the charge transport in the IPSCs.The devices based on planar NiO x at 50°C and low nickel precursor concentration achieved an enhanced efficiency from 16.14%to 18.17%.This work established an efficient CBD route to fabricate planar NiO x film for PSCs and paved the way for high performance PSCs with CBD-prepared hole transporting materials.展开更多
We report the experimental phenomenon of large resistance change in plasma oxidized TiOx/TiNx film fabricated on W bottom-electrode-contact （W-BEC） array. The W-BEC in diameter 26Ohm is fabricated by a 0.18μm CMOS ...We report the experimental phenomenon of large resistance change in plasma oxidized TiOx/TiNx film fabricated on W bottom-electrode-contact （W-BEC） array. The W-BEC in diameter 26Ohm is fabricated by a 0.18μm CMOS technology, and the TiOx/TiNx cell array is formed by rf magnetron sputtering and reactive ion etching. In current-voltage （I- V） measurement for current-sweeping mode, large snap-back of voltage is observed, which indicates that the sample changes from high-resistance state （HRS） to low-resistance state （LRS）. In the I-V measurement for voltage-sweeping mode, large current collapse is observed, which indicates that the sample changes from LRS to HRS. The current difference between HRS and LRS is about two orders. The threshold current and voltage for the resistance change is about 5.0- 10^-5 A and 2.5 V, respectively. The pulse voltage can also change the resistance and the pulse time is as shorter as 30 ns for the resistance change. These properties of TiOx/TiNx film are comparable to that of conventional phase-change material, which makes it possible for RRAM application.展开更多
By electrodeposition in organic system,NiO films with reversible electrochromic property were fabricated.Fluorine-doped tin oxide glass slices were used as substrates,i.e.cathodes.Cyclic voltammetry and ultraviolet-vi...By electrodeposition in organic system,NiO films with reversible electrochromic property were fabricated.Fluorine-doped tin oxide glass slices were used as substrates,i.e.cathodes.Cyclic voltammetry and ultraviolet-visible transmission spectroscopy were adopted to study the electrochromic properties of the films.High resolution transmission electron microscopy(HRTEM) was employed to analyze the composition and structure of the films.It is found that the films are composed of fine NiO crystal grains of a few nanometers in diameter,endowing them with large visible light transmittance variation,rapid switch rate(i.e.rapid response time) between the bleached and colored states.Their cycling durability reached 6000 cycles.展开更多
The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately ...The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.展开更多
基金financially supported by the Military Pre-Research fund(No.9140A12040412DZ02138)
文摘NiO films were fabricated by reactive direct current magnetron sputtering on glass and alumina substrates for the application in energetic nano-multilayers. The structural and thermal properties of the films were investigated with the volume ratio of oxygen to argon ranging from 1：9 to 3：2, and the optimized ratio value is obtained as 1：3, which was confirmed by X-ray diffraction （XRD）, atomic force microscopy and ultrafast measure- ment system. The effect of the film thickness, varying from 150 to 900 nm, on the structural properties was characterized by XRD and scanning electron microscopy （SEM）. XRD analysis reveals that the （111） lattice plane is the preferred orientation. The intensities of preferential peaks and the grain sizes increase as the film thicknesses increase.
基金supported by the Special Support Program for High-level Talents of Shaanxi Province(No.2020-44)Innnovative Talent Project of China and The Youth Innovation Team of Shaanxi Universities
文摘NiO,an anodic electrochromic material,has applications in energy-saving windows,intelligent displays,and military camouflage.However,its electrochromic mechanism and reasons for its performance degradation in alkaline aqueous electrolytes are complex and poorly understood,making it challenging to improve NiO thin films.We studied the phases and electrochemical characteristics of NiO films in different states(initial,colored,bleached and after 8000 cycles)and identified three main reasons for performance degradation.First,Ni(OH)_(2)is generated during electrochromic cycling and deposited on the NiO film surface,gradually yielding a NiO@Ni(OH)_(2)core-shell structure,isolating the internal NiO film from the electrolyte,and preventing ion transfer.Second,the core-shell structure causes the mode of electrical conduction to change from first-to second-order conduction,reducing the efficiency of ion transfer to the surface Ni(OH)_(2)layer.Third,Ni(OH)_(2)and NiOOH,which have similar crystal structures but different b-axis lattice parameters,are formed during electrochromic cycling,and large volume changes in the unit cell reduce the structural stability of the thin film.Finally,we clarified the mechanism of electrochromic performance degradation of NiO films in alkaline aqueous electrolytes and provide a route to activation of NiO films,which will promote the development of electrochromic technology.
基金supported by the Jilin Provincial Scientific and Technological Development Program(No.20220101036JC)。
文摘By doping with Mg atoms,the bandgap of Mg-doped NiO thin films can be adjusted larger.By using NiO and MgO as sputtering targets,Mg-doped NiO thin films were deposited using radio-frequency magnetron co-sputtering method in pure argon and pure oxygen gas,respectively.The crystal structure,morphological characteristics,composition and optical properties of the obtained films were compared by X-ray diffraction(XRD),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and ultraviolet(UV)-visible spectrophotometer.The properties of the thin films deposited in different sputtering gases are quite different.For the films deposited in pure argon gas,it is a polycrystalline thin film with(200)preferred orientation,while the film deposited in pure oxygen has no preferred orientation.The grain size,molar ratio of Mg to Ni atoms and optical bandgap are larger for the films deposited in pure argon gas than those deposited in oxygen gas.
基金supported by the Key Science and Technology Innovation Team of Shaanxi Province(No.2014KCT-03)Special Support Program for High-level Talents of Shaanxi Province(No.2020-44)China Postdoctoral Science Foundation(No.2019M663990).
文摘Inorganic metal oxide electrochromic materials have good application prospects for energy-saving windows in buildings and smart display applications.Therefore,the development of electrochromic films with good cycling stabilities,fast color-change response times,and high coloring efficiencies has attracted considerable attention.In this study,nanoflake Li-doped NiO electrochromic films were prepared using a hydrothermal method,and the films exhibited superior electrochromic performances in the LiOH electrolyte.Li^(+)ions doping increased the ion transmission rates of the NiO films,and effectively promoted the transportation of ions from the electrolyte into NiO films.Meanwhile,the nanoflake microstructure caused the NiO films to have larger specific surface areas,providing more active sites for electrochemical reactions.It was determined that the NiO-Li20%film exhibited an ultra-fast response in the LiOH electrolyte(coloring and bleaching times reached 3 and 1.5 s,respectively).Additionally,the coloration efficiency was 62.1 cm^(2)C^(−1),and good cycling stability was maintained beyond 1500 cycles.Finally,the simulation calculation results showed that Li doping weakened the adsorption strengths of the NiO films to OH^(−),which reduced the generation and decomposition of NiOOH and helped to improve the cycling stabilities of the films.Therefore,the research presented in this article provides a strategy for designing electrochromic materials in the future.
基金supported by the National Key Re-search and Development Plan(2017YFE0131900,2019YFE0107200)the National Natural Science Foundation of China(52072284,21875178,91963209)+1 种基金the Science and Technology Department of Hubei Province(2020CFB427)Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory(XHD2020-001).
文摘As a convenient,low-cost and up-scalable solution route,chemical bath deposition(CBD)has exhibited impressive advantages in fabricating electron transporting materials like SnO_(2),achieving record efficien-cies for regular n-i-p perovskite solar cells(PSCs).However,for the hysteresis-free and potentially more stable inverted p-i-n PSCs,CBD processing is rarely studied to improve the device performance.In this work,we first present a CBD planar NiO x film as the efficient hole transport layer for the inverted per-ovskite solar cells(IPSCs).The morphologies and semiconducting properties of the NiO x film can be ad-justed by varying the concentration of[Ni(H 2 O)x(NH 3)6-x]2+cation via in-situ monitoring of the CBD re-action process.The characterizations of ultraviolet photoelectron spectroscopy,transient absorption spec-troscopy,time-resolved photoluminescence suggest that the CBD planar NiO x film possesses enhanced conductivity and aligned energy band levels with perovskite,which benefits for the charge transport in the IPSCs.The devices based on planar NiO x at 50°C and low nickel precursor concentration achieved an enhanced efficiency from 16.14%to 18.17%.This work established an efficient CBD route to fabricate planar NiO x film for PSCs and paved the way for high performance PSCs with CBD-prepared hole transporting materials.
基金Supported by the National Basic Research Program of China under Grant No 2006CB302700, the National High Technology Development Programme of China under Grant No 2006AA03Z360~ Chinese Academy of Sciences （Y2005027）, Science and Technology Council of Shanghai under Grant Nos AM0517, 05JC14076, 0552nm043, 06QA14060, 06XD14025, 0652nm003, and 06DZ22017, the China Postdoctoral Science Foundation, and the K. C. Wong Education Foundation （Hong Kong）.
文摘We report the experimental phenomenon of large resistance change in plasma oxidized TiOx/TiNx film fabricated on W bottom-electrode-contact （W-BEC） array. The W-BEC in diameter 26Ohm is fabricated by a 0.18μm CMOS technology, and the TiOx/TiNx cell array is formed by rf magnetron sputtering and reactive ion etching. In current-voltage （I- V） measurement for current-sweeping mode, large snap-back of voltage is observed, which indicates that the sample changes from high-resistance state （HRS） to low-resistance state （LRS）. In the I-V measurement for voltage-sweeping mode, large current collapse is observed, which indicates that the sample changes from LRS to HRS. The current difference between HRS and LRS is about two orders. The threshold current and voltage for the resistance change is about 5.0- 10^-5 A and 2.5 V, respectively. The pulse voltage can also change the resistance and the pulse time is as shorter as 30 ns for the resistance change. These properties of TiOx/TiNx film are comparable to that of conventional phase-change material, which makes it possible for RRAM application.
基金sponsored by the Natural Science Foundation of Shandong Province of China (Grant No. ZR2010EM027)the Applied and Basic Research Project (11-2-4-1-(2)-jch) of Qingdao Municipal Science Technology Commission of China
文摘By electrodeposition in organic system,NiO films with reversible electrochromic property were fabricated.Fluorine-doped tin oxide glass slices were used as substrates,i.e.cathodes.Cyclic voltammetry and ultraviolet-visible transmission spectroscopy were adopted to study the electrochromic properties of the films.High resolution transmission electron microscopy(HRTEM) was employed to analyze the composition and structure of the films.It is found that the films are composed of fine NiO crystal grains of a few nanometers in diameter,endowing them with large visible light transmittance variation,rapid switch rate(i.e.rapid response time) between the bleached and colored states.Their cycling durability reached 6000 cycles.
基金supported by the Natural Science Foundation of Chongqing City(Grant Nos.CSTB2022NSCQ-MSX0751 and cstc2021jcyj-msxmX0500)the Education Department Project of Jilin Province(Grant No.JJKH20220726KJ)+1 种基金the Science and Technology Department Project of Jilin Province(Grant No.20200201077JC)the National Natural Science Foundation of China(Grant No.U2141239).
文摘The choice of cathode and anode materials for electrochromic devices plays a key role in the performance of electrochromic smart windows.In this research,WO_(3)/Ag and TiO_(2)/NiO composite thin films were separately prepared by the hydrothermal method combined with electrodeposition.The electrochromic properties of the single WO_(3) thin film were optimized,and TiO_(2)/NiO composite films showed better electrochromic performance than that of the single NiO film.WO_(3)/Ag and TiO_(2)/NiO composite films with excellent electrochromic properties were respectively chosen as the cathode and the anode to construct a WO_(3)/Ag‒TiO_(2)/NiO electrochromic device.The response time(tc=4.08 s,tb=1.08 s),optical modulation range(35.91%),and coloration efficiency(30.37 cm^(2)·C^(-1))of this electrochromic device are better than those of WO_(3)-NiO and WO_(3)/Ag-NiO electrochromic devices.This work provides a novel research idea for the performance enhancement of electrochromic smart windows.
