The resistive switching memory characteristics of 100 randomly measured devices were observed by reducing device size in a Cr/Cr Ox/Ti Ox/Ti N structure for the first time.Transmission electron microscope image confir...The resistive switching memory characteristics of 100 randomly measured devices were observed by reducing device size in a Cr/Cr Ox/Ti Ox/Ti N structure for the first time.Transmission electron microscope image confirmed a viahole size of 0.4 lm.A 3-nm-thick amorphous Ti Oxwith 4-nm-thick polycrystalline Cr Oxlayer was observed.A small 0.4-lm device shows reversible resistive switching at a current compliance of 300 l A as compared to other larger size devices(1–8 lm)owing to reduction of leakage current through the Ti Oxlayer.Good device-to-device uniformity with a yield of[85%has been clarified by weibull distribution owing to higher slope/shape factor.The switching mechanism is based on oxygen vacancy migration from the Cr Oxlayer and filament formation/rupture in the Ti Oxlayer.Long read pulse endurance of[105cycles,good data retention of 6 h,and a program/erase speed of 1 ls pulse width have been obtained.展开更多
Plasma-assisted chemical vapor deposition (PCVD) was applied for amorphous TiOx deposition on Pyrex-glass substrate at low temperature below 90°C to control orientation of anatase-TiO2 layer by low pressure chemi...Plasma-assisted chemical vapor deposition (PCVD) was applied for amorphous TiOx deposition on Pyrex-glass substrate at low temperature below 90°C to control orientation of anatase-TiO2 layer by low pressure chemical vapor deposition (LPCVD) using TTIP-single precursor. Preferentially -oriented anatase-TiO2 layer was successfully deposited with the orientation ratio as high as 68% on the initial layer of the thickness around 70 nm. Contact angle water was quickly decreased by UV-irradiation on the highly -oriented TiO2 layer comparing with the layer directly deposited on glass, whereas surface roughness on the former was significantly reduced in comparison to that on the latter. Methyleneblue (MB) aqueous solution with the concentration of 2 mmol/L was used to evaluate photocatalytic property on the layer. Rate constant of MB-decomposition via first order kinetics increased with the orientation ratio above 60% was resulted in 2.3 × 10-1?min-1 for the layer with -orientation ratio of 68%, whereas the constant was 2.8 × 10-3 min-1 for the layer directly deposited on glass.展开更多
采用沈阳CK-3高真空磁控溅射薄膜沉积设备在K9玻璃衬底上分别制备了衬底温度为150℃、200℃和250℃的氧化钛薄膜。XRD分析显示这三种温度制备的薄膜由于制备温度不高均没有明显衍射峰,为非晶薄膜。薄膜的光学常数由德国SENTECH SE 850...采用沈阳CK-3高真空磁控溅射薄膜沉积设备在K9玻璃衬底上分别制备了衬底温度为150℃、200℃和250℃的氧化钛薄膜。XRD分析显示这三种温度制备的薄膜由于制备温度不高均没有明显衍射峰,为非晶薄膜。薄膜的光学常数由德国SENTECH SE 850型光谱型椭偏仪对薄膜测试得到,测试波长为300 nm～800 nm,采用Cauchy模型对测试结果进行拟合。结果发现随着制备衬底温度的增大,薄膜的折射率n和消光系数k都随着增大。在衬底温度从150℃增大到250℃时,薄膜的光学带隙从3.46 eV减小到3.02 eV。展开更多
Developing industrially moldable catalysts with harmonized redox performance and acidity is of great significance for the efficient disposal of chlorinated volatile organic compounds(CVOCs)in actual exhaust gasses.Her...Developing industrially moldable catalysts with harmonized redox performance and acidity is of great significance for the efficient disposal of chlorinated volatile organic compounds(CVOCs)in actual exhaust gasses.Here,commercial TiO_(2),typically used for molding catalysts,was chosen as the carrier to fabricate a series of Ce_(0.02)Mn_(0-0.24)TiO_(x) materials with different Mn doping ratios and employed for chlorobenzene(CB)destruction.The introduction of Mn remarkedly facilitated the synergistic effect of each element via the electron transfer processes:Ce^(3+)+Mn^(4+/3+)■Ce^(4+)+Mn^(3+/2+)and Mn^(4+/3+)+Ti^(4+)■Mn^(3+/2+)+Ti^(3+).These synergistic interactions in Ce_(0.02)Mn_(0.04-0.24)TiO_(x),especially Ce_(0.02)Mn_(0.16)TiO_(x),significantly elevated the active oxygen species,oxygen vacancies and redox properties,endowing the superior catalytic oxidation of CB.When the Mn doping amount increased to 0.24,a separate Mn_(3)O_(4) phase appeared,which in turn might weaken the synergistic effect.Furthermore,the acidity of Ce_(0.02)Mn_(0.04-0.24)TiO_(x) was decreased with the Mn doping,regulating the balance of redox property and acidity.Notably,Ce_(0.02)Mn_(0.16)TiO_(x) featured relatively abundant B-acid sites.Its coordinating redox ability and moderate acidity promoted the deep oxidation of CB and RCOOH-intermediates,as well as the rapid desorption of Cl species,thus obtaining sustainable reactivity.In comparison,CeTiO_(x) owned the strongest acidity,however,its poor redox property was not sufficient for the timely oxidative decomposition of the easier adsorbed CB,resulting in its rapid deactivation.This finding provides a promising strategy for the construction of efficient commercial molding catalysts to decompose the industrial-scale CVOCs.展开更多
基金supported by Ministry of Sci ence and Technology(MOST)Taiwan,under Contract no.NSC-1022221-E-182-057-MY2grateful to EOL/ITRI Hsinchu,Taiwan for their experimental support
文摘The resistive switching memory characteristics of 100 randomly measured devices were observed by reducing device size in a Cr/Cr Ox/Ti Ox/Ti N structure for the first time.Transmission electron microscope image confirmed a viahole size of 0.4 lm.A 3-nm-thick amorphous Ti Oxwith 4-nm-thick polycrystalline Cr Oxlayer was observed.A small 0.4-lm device shows reversible resistive switching at a current compliance of 300 l A as compared to other larger size devices(1–8 lm)owing to reduction of leakage current through the Ti Oxlayer.Good device-to-device uniformity with a yield of[85%has been clarified by weibull distribution owing to higher slope/shape factor.The switching mechanism is based on oxygen vacancy migration from the Cr Oxlayer and filament formation/rupture in the Ti Oxlayer.Long read pulse endurance of[105cycles,good data retention of 6 h,and a program/erase speed of 1 ls pulse width have been obtained.
文摘Plasma-assisted chemical vapor deposition (PCVD) was applied for amorphous TiOx deposition on Pyrex-glass substrate at low temperature below 90°C to control orientation of anatase-TiO2 layer by low pressure chemical vapor deposition (LPCVD) using TTIP-single precursor. Preferentially -oriented anatase-TiO2 layer was successfully deposited with the orientation ratio as high as 68% on the initial layer of the thickness around 70 nm. Contact angle water was quickly decreased by UV-irradiation on the highly -oriented TiO2 layer comparing with the layer directly deposited on glass, whereas surface roughness on the former was significantly reduced in comparison to that on the latter. Methyleneblue (MB) aqueous solution with the concentration of 2 mmol/L was used to evaluate photocatalytic property on the layer. Rate constant of MB-decomposition via first order kinetics increased with the orientation ratio above 60% was resulted in 2.3 × 10-1?min-1 for the layer with -orientation ratio of 68%, whereas the constant was 2.8 × 10-3 min-1 for the layer directly deposited on glass.
基金supported by the National Key R&D Program of China(No.2020YFC1910100)the National Natural Science Foundation of China(Nos.22006156 and 21876193)+1 种基金the Chengdu Science and Technology Bureau(No.2018-ZM01-00019-SN)the Youth Innovation Promotion Association CAS。
文摘Developing industrially moldable catalysts with harmonized redox performance and acidity is of great significance for the efficient disposal of chlorinated volatile organic compounds(CVOCs)in actual exhaust gasses.Here,commercial TiO_(2),typically used for molding catalysts,was chosen as the carrier to fabricate a series of Ce_(0.02)Mn_(0-0.24)TiO_(x) materials with different Mn doping ratios and employed for chlorobenzene(CB)destruction.The introduction of Mn remarkedly facilitated the synergistic effect of each element via the electron transfer processes:Ce^(3+)+Mn^(4+/3+)■Ce^(4+)+Mn^(3+/2+)and Mn^(4+/3+)+Ti^(4+)■Mn^(3+/2+)+Ti^(3+).These synergistic interactions in Ce_(0.02)Mn_(0.04-0.24)TiO_(x),especially Ce_(0.02)Mn_(0.16)TiO_(x),significantly elevated the active oxygen species,oxygen vacancies and redox properties,endowing the superior catalytic oxidation of CB.When the Mn doping amount increased to 0.24,a separate Mn_(3)O_(4) phase appeared,which in turn might weaken the synergistic effect.Furthermore,the acidity of Ce_(0.02)Mn_(0.04-0.24)TiO_(x) was decreased with the Mn doping,regulating the balance of redox property and acidity.Notably,Ce_(0.02)Mn_(0.16)TiO_(x) featured relatively abundant B-acid sites.Its coordinating redox ability and moderate acidity promoted the deep oxidation of CB and RCOOH-intermediates,as well as the rapid desorption of Cl species,thus obtaining sustainable reactivity.In comparison,CeTiO_(x) owned the strongest acidity,however,its poor redox property was not sufficient for the timely oxidative decomposition of the easier adsorbed CB,resulting in its rapid deactivation.This finding provides a promising strategy for the construction of efficient commercial molding catalysts to decompose the industrial-scale CVOCs.
