The influence of amorphous TiO_(2) seeding layers on the phase composition of lead magnesium niobate-lead titanate(0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3,PMN-PT)films deposited on Pt/Ti/SiO2/Si substrate by RF magnetron sputte...The influence of amorphous TiO_(2) seeding layers on the phase composition of lead magnesium niobate-lead titanate(0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3,PMN-PT)films deposited on Pt/Ti/SiO2/Si substrate by RF magnetron sputtering was examined.The relation between seeding layer thickness and phase composition at different post annealing temperature was observed by XRD.The thickness of amorphous TiO2 seeding layer and post annealing temperature had remarkable effects on PMN-PT film phase composition.When amorphous seeding layer becomes thick,a new phase of Nb2O5 exists in the films.Only when the seeding layer thickness is suitable,the film with pure perovskite phase can be attained.展开更多
Ni80Fe20/Ni48Fe12Cr40 bilayer films and Ni80Fe20 monolayer films were deposited at room temperature on SiO2/Si（100） substrates by electron beam evaporation. The influence of the thickness of the Ni48Fe12Cr40 underla...Ni80Fe20/Ni48Fe12Cr40 bilayer films and Ni80Fe20 monolayer films were deposited at room temperature on SiO2/Si（100） substrates by electron beam evaporation. The influence of the thickness of the Ni48Fe12Cr40 underlayer on the structure, magnetization, and magnetoresistance of the Ni80Fe20/Ni48Fe12Cr40 bilayer film was investigated. The thickness of the Ni48Fe12Cr40 layer varied from about 1 nm to 18 nm while the Ni80Fe20 layer thickness was fixed at 45 nm. For the as-deposited bilayer films the introducing of the Ni48Fe12Cr40 underlayer promotes both the （111） texture and grain growth in the Ni80Fe20 layer. The Ni48Fe12Cr40 underlayer has no significant influence on the magnetic moment of the Ni80Fe20/Ni48Fe12Cr40 bilayer film. However, the coercivity of the bilayer film changes with the thickness of the Ni48Fe12Cr40 undedayer. The optimum thickness of the Ni48Fe12Cr40 underlayer for improving the anisotropic magnetoresistance effect of the Ni80Fe20/Ni48Fe12Cr40 bilayer film is about 5 nm. With a decrease in temperature from 300 K to 81 K, the anisotropic magnetoresistance ratio of the Ni80Fe20 （45 nm）/Ni48Fe12Cr40 （5 nm） bilayer film increases linearly from 2.1% to 4.8% compared with that of the Ni80Fe20 monolayer film from 1.7% to 4.0%.展开更多
PbZr0.53Ti0.47O3 (PZT) ferroelectric thin films were deposited on LaNiO3 (LNO) by sol-gel method. The PbTiO3 (PT) seed layer was depos-ited between the LNO buffer layer and stainless steel (SS) substrate, which effect...PbZr0.53Ti0.47O3 (PZT) ferroelectric thin films were deposited on LaNiO3 (LNO) by sol-gel method. The PbTiO3 (PT) seed layer was depos-ited between the LNO buffer layer and stainless steel (SS) substrate, which effectively decreased the annealing temperature of LNO layer from 750 C to 650 C. X-ray diffraction (XRD) reveals that LNO layers with PT layer crystallize into a perovskite phase on annealing at 650 C for 10 min. PZT deposited on LNO buffer layer with PT seed layer exhibits good ferroelectric property.展开更多
The metal organic deposition(MOD)method was used for the epitaxial growth of the CeO2/La2Zr2O7(LZO)/LZO seed layer structure on a cube-textured Ni5W substrate layer by layer.The material phase and the macro-orientatio...The metal organic deposition(MOD)method was used for the epitaxial growth of the CeO2/La2Zr2O7(LZO)/LZO seed layer structure on a cube-textured Ni5W substrate layer by layer.The material phase and the macro-orientations were analyzed by XRD.The surface morphology and the blocking performance of the buffer layer were investigated by SEM and AES.The grain orientation and the crystallographic growth mode of the CeO2 layer were first characterized by electron backscattering diffraction(EBSD).The uniformly distributed islanded LZO seed layer optimized both the in-plan and the out-plan orientation of the CeO2/LZO buffer layers,and the CeO2/LZO buffer layers with a thickness of 175 nm acted as an efficient Ni,W barrier.The EBSD analysis indicated that the crystallographic orientation of each layer can be obtained at various accelerating voltages for the multilayer sample,the percentage of{001}<110>rotated cube texture of CeO2 layer reaching 97.4%at the accelerating voltage of 15 kV,thus showing epitaxial deposition with a high texture.展开更多
The deposition of a Cu seed layer film is investigated by supercritical fluid deposition （SCFD） using H2 as a reducing agent for Bis（2,2,6,6-tetramethyl-3,5- heptanedionato） copper in supercritical CO2 （scCO2）. ...The deposition of a Cu seed layer film is investigated by supercritical fluid deposition （SCFD） using H2 as a reducing agent for Bis（2,2,6,6-tetramethyl-3,5- heptanedionato） copper in supercritical CO2 （scCO2）. The effects of deposition temperature, precursor, and H2 concentration are investigated to optimize Cu deposition. Continuous metallic Cu films are deposited on Ru substrates at 190 ℃ when a 0.002 mol/L Cu precursor is introduced with 0.75 mol/L H2. A Cu precursor concentration higher than 0.002 mol/L is found to have negative effects on the surface qualities of Cu films. For a H2 concentration above 0.56 mol/L, the root-mean-square （RMS） roughness of a Cu film decreases as the H2 concentration increases. Finally, a 20-nm thick Cu film with a smooth surface, which is required as a seed layer in advanced interconnects, is successfully deposited at a high H2 concentration （0.75 tool/L）.展开更多
The c-axis oriented hcp-Co_(81)Ir_(19)magnetic films were prepared on different seed layers(Ni,Cu,Ir,Pt,Au,and No seed).We systematically investigated the impact that surface-free energy and strain energy have on the ...The c-axis oriented hcp-Co_(81)Ir_(19)magnetic films were prepared on different seed layers(Ni,Cu,Ir,Pt,Au,and No seed).We systematically investigated the impact that surface-free energy and strain energy have on the orientation and defects and/or internal stress of the grains by increasing the lattice mismatch ratio.Moreover,the initial permeability and the natural resonance frequency were discussed in great detail using a comparison between calculated values and experimental values.We found that the almost unchanged 4πM_(s) andμ_(i) are not affected,while the changed H_(c),intrinsic K_(grain),and f_(r) are strongly dependent on the seed layer and seed layer material.Moreover,the extracted damping constant is sensitive to the defects and/or internal stress and orientation of the grains.Therefore,the soft magnetic properties and microwave properties are adjusted and optimized by seed layers with different materials.展开更多
The effect of seed layer on the orientation of ZnO film was investigated. Before the preparation of ZnO film using sol-gel method, seed layer of ZnO was prepared in a similar way using the precursor at a rather low co...The effect of seed layer on the orientation of ZnO film was investigated. Before the preparation of ZnO film using sol-gel method, seed layer of ZnO was prepared in a similar way using the precursor at a rather low concentration. Experiments show that the existence of seed layer can improve the orientation of the finally prepared ZnO film, while baking temperature, baking time and precursor concentration all have effects on the final results.展开更多
We have grown PbMg1/3Nb2/3O3-PbTiO3(PMN-PT) thin films by radio frequency(RF) sputtering deposition at 550 ℃-650 ℃ on Pt/Ti/SiO2/Si and TiO2/Pt/Ti/SiO2/Si substrates.The phase compositions and microstructure of thin...We have grown PbMg1/3Nb2/3O3-PbTiO3(PMN-PT) thin films by radio frequency(RF) sputtering deposition at 550 ℃-650 ℃ on Pt/Ti/SiO2/Si and TiO2/Pt/Ti/SiO2/Si substrates.The phase compositions and microstructure of thin films were characterized by X-ray diffraction(XRD) and scanning electric microstructure(SEM).The effect of the TiO2 seed layer on PMN-PT films was studied.展开更多
Crystalline(Na_(1-x)K_(x))NbO_(3)(NKN)thin films were deposited on Sr_(2)Nb_(3)O_(10)/TiN/Si(S-TS)substrates at 370°C.Sr_(2)Nb_(3)O_(10)(SNO)nanosheets served as a template for the formation of crystalline NKN fi...Crystalline(Na_(1-x)K_(x))NbO_(3)(NKN)thin films were deposited on Sr_(2)Nb_(3)O_(10)/TiN/Si(S-TS)substrates at 370°C.Sr_(2)Nb_(3)O_(10)(SNO)nanosheets served as a template for the formation of crystalline NKN films at low temperatures.When the NKN film was deposited on one SNO monolayer,the NKN memristor exhibited normal bipolar switching characteristics,which could be attributed to the formation and destruction of oxygen vacancy filaments.Moreover,the NKN memristor with one SNO monolayer exhibited artificial synaptic properties.However,the NKN memristor deposited on two SNO monolayers exhibited self-rectifying bipolar switching properties,with the two SNO monolayers acting as tunneling barriers in the memristor.The conduction mechanism of the NKN memristor with two SNO monolayers in the highresistance state is attributed to Schottky emission,direct tunneling,and Fowler–Nordheim(FN)tunneling.The current conduction in this memristor in the low-resistance state was governed by direct tunneling and FN tunneling.Additionally,the NKN memristor with two SNO monolayers exhibited large ON/OFF and rectification ratios and artificial synaptic properties.Therefore,an NKN memristor with two SNO monolayers can be used for fabricating artificial synaptic devices with a cross-point array structure.展开更多
Despite being an excellent candidate for a photocathode,Cu_(2)ZnSnS_4(CZTS)performance is limited by suboptimal bulk and interfacial charge carrier dynamics.In this work,we introduce a facile and versatile CZTS precur...Despite being an excellent candidate for a photocathode,Cu_(2)ZnSnS_4(CZTS)performance is limited by suboptimal bulk and interfacial charge carrier dynamics.In this work,we introduce a facile and versatile CZTS precursor seed layer engineering technique,which significantly enhances crystal growth and mitigates detrimental defects in the postsulfurized CZTS light-absorbing films.This effective optimization of defects and charge carrier dynamics results in a highly efficient CZTS/CdS/TiO_(2)/Pt thin-film photocathode,achieving a record half-cell solar-to-hydrogen(HC-STH)conversion efficiency of 9.91%.Additionally,the photocathode exhibits a highest photocurrent density(J_(ph))of 29.44 m A cm^(-2)(at 0 VRHE)and favorable onset potential(Von)of 0.73 VRHE.Furthermore,our CTZS photocathode demonstrates a remarkable Jph of 16.54 m A cm^(-2)and HC-STH efficiency of 2.56%in natural seawater,followed by an impressive unbiased STH efficiency of 2.20%in a CZTS-BiVO_4 tandem cell.The scalability of this approach is underscored by the successful fabrication of a 4×4 cm^(2)module,highlighting its significant potential for practical,unbiased in situ solar seawater splitting applications.展开更多
Nanostructured catalyst-integrated electrodes with remarkably reduced catalyst loadings,high catalyst utilization and facile fabrication are urgently needed to enable cost-effective,green hydrogen production via proto...Nanostructured catalyst-integrated electrodes with remarkably reduced catalyst loadings,high catalyst utilization and facile fabrication are urgently needed to enable cost-effective,green hydrogen production via proton exchange membrane electrolyzer cells(PEMECs).Herein,benefitting from a thin seeding layer,bottom-up grown ultrathin Pt nanosheets(Pt-NSs)were first deposited on thin Ti substrates for PEMECs via a fast,template-and surfactant-free electrochemical growth process at room temperature,showing highly uniform Pt surface coverage with ultralow loadings and vertically well-aligned nanosheet morphologies.Combined with an anode-only Nafion 117 catalyst-coated membrane(CCM),the Pt-NS electrode with an ultralow loading of 0.015 mgPt cm−2 demonstrates superior cell performance to the commercial CCM(3.0 mgPt cm^(−2)),achieving 99.5%catalyst savings and more than 237-fold higher catalyst utilization.The remarkable performance with high catalyst utilization is mainly due to the vertically well-aligned ultrathin nanosheets with good surface coverage exposing abundant active sites for the electrochemical reaction.Overall,this study not only paves a new way for optimizing the catalyst uniformity and surface coverage with ultralow loadings but also provides new insights into nanostructured electrode design and facile fabrication for highly efficient and low-cost PEMECs and other energy storage/conversion devices.展开更多
In the absence of commonly used seed layer, we can still successfully synthesized aligned ZnO nanowire arrays by the hydrothermal method. By using aluminum-doped zinc oxide(AZO) glass as a substrate, high-density and ...In the absence of commonly used seed layer, we can still successfully synthesized aligned ZnO nanowire arrays by the hydrothermal method. By using aluminum-doped zinc oxide(AZO) glass as a substrate, high-density and vertically aligned ZnO nanowires were synthesized directly on the substrate in the absence of the ZnO seed layer. The current-voltage curve indicated that the sample grown on AZO glass substrate in the absence of seed layer possesses better conductivity than that synthesized on FTO glass substrate with ZnO seed layer. Thus, a simplified, seed-free and low-cost experimental protocol was reported here for large-scale production of high quality ZnO nanowire arrays with promoted conductivity.展开更多
The barrier/seed layer is a key issue in Through Silicon Via （TSV） technology for 3-D integration. Sputtering is an important deposition method for via metallization in semiconductor process. However, due to the lim...The barrier/seed layer is a key issue in Through Silicon Via （TSV） technology for 3-D integration. Sputtering is an important deposition method for via metallization in semiconductor process. However, due to the limitation of sputtering and a ＂scallop＂ profile inside vias, poor step coverage of the barrier/seed layer always occurs in the via metallization process. In this paper, the effects of several sputter parameters （DC power, Ar pressure, deposition time, and substrate temperature） on thin film coverage for TSV applications are investigated. Robust TSVs with aspect ratio 5 ： 1 were obtained with optimized magnetron sputter parameters. In addition, the influences of different sputter parameters are compared and the conclusion could be used as a guideline to select appropriate parameter sets.展开更多
Using plasma enhanced chemical vapor deposition（PECVD） at 13.56 MHz,a seed layer is fabricated at the initial growth stage of the hydrogenated microcrystalline silicon germanium(μc-Si1-xGex:H) i-layer.The effects o...Using plasma enhanced chemical vapor deposition（PECVD） at 13.56 MHz,a seed layer is fabricated at the initial growth stage of the hydrogenated microcrystalline silicon germanium(μc-Si1-xGex:H) i-layer.The effects of seeding processes on the growth ofμc-Si1-xGex:H i-layers and the performance ofμc-Si1-xGex:H p-i-n single junction solar cells are investigated.By applying this seeding method,theμc-Si1-xGex:H solar cell shows a significant improvement in short circuit current density(Jsc) and fill factor（FF） with an acceptable performance of blue response as aμc-Si:H solar cell even when the Ge content x increases up to 0.3.Finally,an improved efficiency of 7.05%is achieved for theμc-Si0.7Ge0.3:H solar cell.展开更多
The growth of polycrystalline silicon layers on glass from tin solutions at low temperatures is presented.This approach is based on the steady-state solution growth of Si crystallites on nanocrystalline seed layers, w...The growth of polycrystalline silicon layers on glass from tin solutions at low temperatures is presented.This approach is based on the steady-state solution growth of Si crystallites on nanocrystalline seed layers, which are prepared in a preceding process step. Scanning electron microscopy and atomic force microscopy investigations reveal details about the seed layer surfaces, which consist of small hillocks, as well as about Sn inclusions and gaps along the glass substrate after solution growth. The successful growth of continuous microcrystalline Si layers with grain sizes up to several ten micrometers shows the feasibility of the process and makes it interesting for photovoltaics.展开更多
Efficient indium tin oxide （ITO）-free inverted polymer solar cells （PSCs） were fabricated by applying ultrathin metal transparent electrodes as sunlight incident electrodes. Smooth and continuous Ag film of 4 nm t...Efficient indium tin oxide （ITO）-free inverted polymer solar cells （PSCs） were fabricated by applying ultrathin metal transparent electrodes as sunlight incident electrodes. Smooth and continuous Ag film of 4 nm thickness was developed through the introduction of a 2 nm Au seed layer. Ultrathin Ag transparent electrode with an average transmittance of up to 80% from 480 to 680 nm and a sheet resistance of 35.4Ω/sq was obtained through the introduction of a ZnO anti-reflective layer. The ultrathin metal electrode could be directly used as cathode in polymer solar cells without oxygen plasma treatment. ITO-free inverted PSCs obtained a power conversion efficiency （PCE） of 5.2% by utilizing the ultrathin metal transparent electrodes. These results demonstrated a simple method of fabricating ITO-free inverted PSCs.展开更多
文摘The influence of amorphous TiO_(2) seeding layers on the phase composition of lead magnesium niobate-lead titanate(0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3,PMN-PT)films deposited on Pt/Ti/SiO2/Si substrate by RF magnetron sputtering was examined.The relation between seeding layer thickness and phase composition at different post annealing temperature was observed by XRD.The thickness of amorphous TiO2 seeding layer and post annealing temperature had remarkable effects on PMN-PT film phase composition.When amorphous seeding layer becomes thick,a new phase of Nb2O5 exists in the films.Only when the seeding layer thickness is suitable,the film with pure perovskite phase can be attained.
文摘Ni80Fe20/Ni48Fe12Cr40 bilayer films and Ni80Fe20 monolayer films were deposited at room temperature on SiO2/Si（100） substrates by electron beam evaporation. The influence of the thickness of the Ni48Fe12Cr40 underlayer on the structure, magnetization, and magnetoresistance of the Ni80Fe20/Ni48Fe12Cr40 bilayer film was investigated. The thickness of the Ni48Fe12Cr40 layer varied from about 1 nm to 18 nm while the Ni80Fe20 layer thickness was fixed at 45 nm. For the as-deposited bilayer films the introducing of the Ni48Fe12Cr40 underlayer promotes both the （111） texture and grain growth in the Ni80Fe20 layer. The Ni48Fe12Cr40 underlayer has no significant influence on the magnetic moment of the Ni80Fe20/Ni48Fe12Cr40 bilayer film. However, the coercivity of the bilayer film changes with the thickness of the Ni48Fe12Cr40 undedayer. The optimum thickness of the Ni48Fe12Cr40 underlayer for improving the anisotropic magnetoresistance effect of the Ni80Fe20/Ni48Fe12Cr40 bilayer film is about 5 nm. With a decrease in temperature from 300 K to 81 K, the anisotropic magnetoresistance ratio of the Ni80Fe20 （45 nm）/Ni48Fe12Cr40 （5 nm） bilayer film increases linearly from 2.1% to 4.8% compared with that of the Ni80Fe20 monolayer film from 1.7% to 4.0%.
基金supported by the National Natural Science Foundation of China (No. 50872080)Shanghai Special Foundation of Nanotechnology (No. 1052nm07300)+1 种基金Shanghai Education Development Foundation (No. 08SG41)Shanghai Leading Academic Disciplines (No. S30107)
文摘PbZr0.53Ti0.47O3 (PZT) ferroelectric thin films were deposited on LaNiO3 (LNO) by sol-gel method. The PbTiO3 (PT) seed layer was depos-ited between the LNO buffer layer and stainless steel (SS) substrate, which effectively decreased the annealing temperature of LNO layer from 750 C to 650 C. X-ray diffraction (XRD) reveals that LNO layers with PT layer crystallize into a perovskite phase on annealing at 650 C for 10 min. PZT deposited on LNO buffer layer with PT seed layer exhibits good ferroelectric property.
基金National Basic Research Program"973"of China(2006CB601005)National Natural Science Foundation of China(50771003)National High Technology Research and Development Program of"863"(2009AA032401)
文摘The metal organic deposition(MOD)method was used for the epitaxial growth of the CeO2/La2Zr2O7(LZO)/LZO seed layer structure on a cube-textured Ni5W substrate layer by layer.The material phase and the macro-orientations were analyzed by XRD.The surface morphology and the blocking performance of the buffer layer were investigated by SEM and AES.The grain orientation and the crystallographic growth mode of the CeO2 layer were first characterized by electron backscattering diffraction(EBSD).The uniformly distributed islanded LZO seed layer optimized both the in-plan and the out-plan orientation of the CeO2/LZO buffer layers,and the CeO2/LZO buffer layers with a thickness of 175 nm acted as an efficient Ni,W barrier.The EBSD analysis indicated that the crystallographic orientation of each layer can be obtained at various accelerating voltages for the multilayer sample,the percentage of{001}<110>rotated cube texture of CeO2 layer reaching 97.4%at the accelerating voltage of 15 kV,thus showing epitaxial deposition with a high texture.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 50901086 and 51072118)the Shanghai Shuguang Project,China (Grant No. 09SG46)+2 种基金the Science Foundation for the Excellent Youth Scholars of Shanghai Municipal Education Commission,China (Grant No. slg10032)the Qianjiang Project of Zhejiang Province,China (Grant No. 2010R10047)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry
文摘The deposition of a Cu seed layer film is investigated by supercritical fluid deposition （SCFD） using H2 as a reducing agent for Bis（2,2,6,6-tetramethyl-3,5- heptanedionato） copper in supercritical CO2 （scCO2）. The effects of deposition temperature, precursor, and H2 concentration are investigated to optimize Cu deposition. Continuous metallic Cu films are deposited on Ru substrates at 190 ℃ when a 0.002 mol/L Cu precursor is introduced with 0.75 mol/L H2. A Cu precursor concentration higher than 0.002 mol/L is found to have negative effects on the surface qualities of Cu films. For a H2 concentration above 0.56 mol/L, the root-mean-square （RMS） roughness of a Cu film decreases as the H2 concentration increases. Finally, a 20-nm thick Cu film with a smooth surface, which is required as a seed layer in advanced interconnects, is successfully deposited at a high H2 concentration （0.75 tool/L）.
基金Project supported by the Natural Science Foundation of Ningxia in China (Grant No.2022AAC03288)the Ningxia New Solid Electronic Materials and Devices Research and Development Innovation Team (Grant No.2020CXTDLX12)。
文摘The c-axis oriented hcp-Co_(81)Ir_(19)magnetic films were prepared on different seed layers(Ni,Cu,Ir,Pt,Au,and No seed).We systematically investigated the impact that surface-free energy and strain energy have on the orientation and defects and/or internal stress of the grains by increasing the lattice mismatch ratio.Moreover,the initial permeability and the natural resonance frequency were discussed in great detail using a comparison between calculated values and experimental values.We found that the almost unchanged 4πM_(s) andμ_(i) are not affected,while the changed H_(c),intrinsic K_(grain),and f_(r) are strongly dependent on the seed layer and seed layer material.Moreover,the extracted damping constant is sensitive to the defects and/or internal stress and orientation of the grains.Therefore,the soft magnetic properties and microwave properties are adjusted and optimized by seed layers with different materials.
基金supported by the National Natural Science Foundation of China under grant No.50402011Tianjin Natural Science Foundation under grant No.33608911.
文摘The effect of seed layer on the orientation of ZnO film was investigated. Before the preparation of ZnO film using sol-gel method, seed layer of ZnO was prepared in a similar way using the precursor at a rather low concentration. Experiments show that the existence of seed layer can improve the orientation of the finally prepared ZnO film, while baking temperature, baking time and precursor concentration all have effects on the final results.
文摘We have grown PbMg1/3Nb2/3O3-PbTiO3(PMN-PT) thin films by radio frequency(RF) sputtering deposition at 550 ℃-650 ℃ on Pt/Ti/SiO2/Si and TiO2/Pt/Ti/SiO2/Si substrates.The phase compositions and microstructure of thin films were characterized by X-ray diffraction(XRD) and scanning electric microstructure(SEM).The effect of the TiO2 seed layer on PMN-PT films was studied.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.2020R1A2B5B01002063)the KU-KIST Graduate School Program of the Korea University。
文摘Crystalline(Na_(1-x)K_(x))NbO_(3)(NKN)thin films were deposited on Sr_(2)Nb_(3)O_(10)/TiN/Si(S-TS)substrates at 370°C.Sr_(2)Nb_(3)O_(10)(SNO)nanosheets served as a template for the formation of crystalline NKN films at low temperatures.When the NKN film was deposited on one SNO monolayer,the NKN memristor exhibited normal bipolar switching characteristics,which could be attributed to the formation and destruction of oxygen vacancy filaments.Moreover,the NKN memristor with one SNO monolayer exhibited artificial synaptic properties.However,the NKN memristor deposited on two SNO monolayers exhibited self-rectifying bipolar switching properties,with the two SNO monolayers acting as tunneling barriers in the memristor.The conduction mechanism of the NKN memristor with two SNO monolayers in the highresistance state is attributed to Schottky emission,direct tunneling,and Fowler–Nordheim(FN)tunneling.The current conduction in this memristor in the low-resistance state was governed by direct tunneling and FN tunneling.Additionally,the NKN memristor with two SNO monolayers exhibited large ON/OFF and rectification ratios and artificial synaptic properties.Therefore,an NKN memristor with two SNO monolayers can be used for fabricating artificial synaptic devices with a cross-point array structure.
基金supported by National Natural Science Foundation of China(No.62474114,52472225)Guangdong Basic and Applied Basic Research Foundation(2025A1515012041,2025A1515011515)China+1 种基金Science and Technology plan project of Shenzhen(JCYJ20240813141620027,20231122102326002)ChinaShenzhen University 2035 Program for Excellent Research(Grants 2024B003)。
文摘Despite being an excellent candidate for a photocathode,Cu_(2)ZnSnS_4(CZTS)performance is limited by suboptimal bulk and interfacial charge carrier dynamics.In this work,we introduce a facile and versatile CZTS precursor seed layer engineering technique,which significantly enhances crystal growth and mitigates detrimental defects in the postsulfurized CZTS light-absorbing films.This effective optimization of defects and charge carrier dynamics results in a highly efficient CZTS/CdS/TiO_(2)/Pt thin-film photocathode,achieving a record half-cell solar-to-hydrogen(HC-STH)conversion efficiency of 9.91%.Additionally,the photocathode exhibits a highest photocurrent density(J_(ph))of 29.44 m A cm^(-2)(at 0 VRHE)and favorable onset potential(Von)of 0.73 VRHE.Furthermore,our CTZS photocathode demonstrates a remarkable Jph of 16.54 m A cm^(-2)and HC-STH efficiency of 2.56%in natural seawater,followed by an impressive unbiased STH efficiency of 2.20%in a CZTS-BiVO_4 tandem cell.The scalability of this approach is underscored by the successful fabrication of a 4×4 cm^(2)module,highlighting its significant potential for practical,unbiased in situ solar seawater splitting applications.
基金The authors greatly appreciate the support from the U.S.Department of Energy’s Office of Energy Efficiency and Renewable Energy(EERE)under the Hydrogen and Fuel Cell Technologies Office Awards DE-EE0008426 and DE-EE0008423National Energy Technology Laboratory under Award DEFE0011585.
文摘Nanostructured catalyst-integrated electrodes with remarkably reduced catalyst loadings,high catalyst utilization and facile fabrication are urgently needed to enable cost-effective,green hydrogen production via proton exchange membrane electrolyzer cells(PEMECs).Herein,benefitting from a thin seeding layer,bottom-up grown ultrathin Pt nanosheets(Pt-NSs)were first deposited on thin Ti substrates for PEMECs via a fast,template-and surfactant-free electrochemical growth process at room temperature,showing highly uniform Pt surface coverage with ultralow loadings and vertically well-aligned nanosheet morphologies.Combined with an anode-only Nafion 117 catalyst-coated membrane(CCM),the Pt-NS electrode with an ultralow loading of 0.015 mgPt cm−2 demonstrates superior cell performance to the commercial CCM(3.0 mgPt cm^(−2)),achieving 99.5%catalyst savings and more than 237-fold higher catalyst utilization.The remarkable performance with high catalyst utilization is mainly due to the vertically well-aligned ultrathin nanosheets with good surface coverage exposing abundant active sites for the electrochemical reaction.Overall,this study not only paves a new way for optimizing the catalyst uniformity and surface coverage with ultralow loadings but also provides new insights into nanostructured electrode design and facile fabrication for highly efficient and low-cost PEMECs and other energy storage/conversion devices.
基金Funded by the Natural Science Foundation of Jiangsu Province of China(Nos.BK20150829)the Scientific Research Foundation of Nanjing University of Posts and Telecommunications,China(Nos.NY215023,NY217094,and Y214014)
文摘In the absence of commonly used seed layer, we can still successfully synthesized aligned ZnO nanowire arrays by the hydrothermal method. By using aluminum-doped zinc oxide(AZO) glass as a substrate, high-density and vertically aligned ZnO nanowires were synthesized directly on the substrate in the absence of the ZnO seed layer. The current-voltage curve indicated that the sample grown on AZO glass substrate in the absence of seed layer possesses better conductivity than that synthesized on FTO glass substrate with ZnO seed layer. Thus, a simplified, seed-free and low-cost experimental protocol was reported here for large-scale production of high quality ZnO nanowire arrays with promoted conductivity.
基金supported by the National Natural Science Foundation of China (No. 61274111)he National Science & Technology Major Project of China (No. 2011ZX02709)
文摘The barrier/seed layer is a key issue in Through Silicon Via （TSV） technology for 3-D integration. Sputtering is an important deposition method for via metallization in semiconductor process. However, due to the limitation of sputtering and a ＂scallop＂ profile inside vias, poor step coverage of the barrier/seed layer always occurs in the via metallization process. In this paper, the effects of several sputter parameters （DC power, Ar pressure, deposition time, and substrate temperature） on thin film coverage for TSV applications are investigated. Robust TSVs with aspect ratio 5 ： 1 were obtained with optimized magnetron sputter parameters. In addition, the influences of different sputter parameters are compared and the conclusion could be used as a guideline to select appropriate parameter sets.
基金supportedbytheNationalBasicResearch Program ofChina(Nos.2011CBA00705,2011CBA00706,2011CBA00707)the Natural Science Foundation of Tianjin(No.12JCQNJC01000)the Fundamental Research Funds for the Central Universities
文摘Using plasma enhanced chemical vapor deposition（PECVD） at 13.56 MHz,a seed layer is fabricated at the initial growth stage of the hydrogenated microcrystalline silicon germanium(μc-Si1-xGex:H) i-layer.The effects of seeding processes on the growth ofμc-Si1-xGex:H i-layers and the performance ofμc-Si1-xGex:H p-i-n single junction solar cells are investigated.By applying this seeding method,theμc-Si1-xGex:H solar cell shows a significant improvement in short circuit current density(Jsc) and fill factor（FF） with an acceptable performance of blue response as aμc-Si:H solar cell even when the Ge content x increases up to 0.3.Finally,an improved efficiency of 7.05%is achieved for theμc-Si0.7Ge0.3:H solar cell.
基金Project supported by the German Research Foundation(DFG)(No.BO 1129/5-1)
文摘The growth of polycrystalline silicon layers on glass from tin solutions at low temperatures is presented.This approach is based on the steady-state solution growth of Si crystallites on nanocrystalline seed layers, which are prepared in a preceding process step. Scanning electron microscopy and atomic force microscopy investigations reveal details about the seed layer surfaces, which consist of small hillocks, as well as about Sn inclusions and gaps along the glass substrate after solution growth. The successful growth of continuous microcrystalline Si layers with grain sizes up to several ten micrometers shows the feasibility of the process and makes it interesting for photovoltaics.
文摘Efficient indium tin oxide （ITO）-free inverted polymer solar cells （PSCs） were fabricated by applying ultrathin metal transparent electrodes as sunlight incident electrodes. Smooth and continuous Ag film of 4 nm thickness was developed through the introduction of a 2 nm Au seed layer. Ultrathin Ag transparent electrode with an average transmittance of up to 80% from 480 to 680 nm and a sheet resistance of 35.4Ω/sq was obtained through the introduction of a ZnO anti-reflective layer. The ultrathin metal electrode could be directly used as cathode in polymer solar cells without oxygen plasma treatment. ITO-free inverted PSCs obtained a power conversion efficiency （PCE） of 5.2% by utilizing the ultrathin metal transparent electrodes. These results demonstrated a simple method of fabricating ITO-free inverted PSCs.
